When is it too long to ask for a letter of recommendation from someone?

IMO, stop by and check with him. It’s always best practice to get the other person’s OK so they know to maybe expect a call. I don’t know that there is a time limit, as long as they can reasonably and truthfully vouch for you. 3 Semesters isn’t that long ago, really. I have a reference from one of my ex-bosses from 10 years ago that I still use. I always call her to let her know I used her again.

Most professors understand that writing letters goes along with the territory. That sounds like a totally reasonable period of time.

What I would do is start by sending the professor an email and ask to set up a time to meet briefly. (“Hi Dr. So-and-so, I hope you’re doing well. I took your Bio 101 class last fall and really enjoyed it. If possible, I’d really appreciate a chance to meet with you in the next few weeks. When is a good time for you?”)

And then you meet and ask for the letter. Bring the paperwork with you and be prepared to explain what you’re applying for and why. If you have a resume or a CV, bring those too since it will be easier for your recommender to write the letter with more information.

I also like to give an easy out in case the person doesn’t want to write the letter—“of course I understand if you’re too busy this quarter” or similar. But I have never heard of a professor actually turning someone down, so you probably don’t have to worry about that.

Good luck! Let us know how it goes.

I visited a couple of old professors from years ago several months ago. They might only have vaguely recollected me, but that’s okay: they asked for some of my old papers so they could jog their memories about what kind of student I was.

I don’t think several years is a problem, as long as you have some of the work you did for them.

1 year.

For a professional aquaintance, probabaly not more than a year or two, but for a personal reference, longer could work. I recently was asked for an evaluation of a man who grew up next door to me, and is now 27 years old. He was applying for a job in Law Enforcement, and they were doing a background check.

I’m beginning to apply to grad schools. I just asked a professor whose class I was in two years ago for a letter of recommendation.
I think as long as the professor remembers who you are that it is okay to ask for a letter of rec. This is one of the reasons why I try to make myself known in my classes and go to office hoursYou never know when you might need some help from them.

Within a couple of years is fine.

I agree with a year or two, maximum. Beyond that, a recommendation loses meaning (you may have significantly changed for the worse since then). With a backround check as @YARNLADY described, reviewers will go back much further as they are interested in your behavior during your formative years and not just a recent snapshot.
See ya….Gary/wtf/lurve whore

I started a graduate program this semester. Prior to applying for it, I hadn’t really kept in touch with any of my professors (even though I knew I wanted to go to graduate school—Very Bad Move). I needed someone knowledgeable about my academic work, which meant going a few years back (2 in my case).

A great recommendation from a professor you really clicked with a few years ago is always going to be better than a lukewarm recommendation from a professor you have now. Always. Especially as many people keep in touch with professors, so not having had a class with them recently isn’t horrible. (Yes, I realize you didn’t really keep in touch.)

The best way to deal with this situation is in person if possible. Drop by their office, explain the situation and that you really enjoyed their course and simply ask for the recommendation. Be prepared to remind them who you are.

If you can’t drop by in person, a nice email will do. Again, remind them who you are—what class you took with them, what projects you did in that class, etc. Talk about your plans for the future. Then ask for the letter.

(Also, listen to @nikipedia, her advice is perfect.)

It is too long if the person either doesn’t remember you at all or has died. For professors being asked to write letters of reference goes with the territory. Professors typically have three requirements placed on them by their university: to publish the results of research, to teach a certain number of classes, and to “serve.” Serving means serving on committees as well as counseling and aiding students, including writing letters of recommendation.

I would say go visit this professor and bring copies of your work so he/she can jog their memory about you.

It depends on the professor. Not too long ago I asked for two, each from professors I had 5 years ago. I had sent a graduation pic of me to jog their memories. Both agreed and seemed happy to be of assistance. I’m guessing they were at least decent, since I got into the competative program I applied to.

Thanks a lot guys =D. I wasn’t too sure and I didn’t want to do something inappropriate (although somehow I know this professor would’ve understood).

Just a few things to keep in mind when asking for letters from your professors.

Write a short note that explains what you are applying to do. Your professor can use that as a guide when he or she begins to compose the letter. It is impossible for a professor to write a useful letter without a clear idea about the purpose for the recommendation.

Make it clear either that the letter needs to be sent directly to some organization (employer or school) or that you will pick up the letter and submit it yourself. If you expect the professor to mail the letter, provide postage and an envelope with the correct address for wherever you want it sent. For form letters, the school or employer usually provides a self-addressed envelope.

Be aware that when a confidential letter is needed, the professor is more candid and may not supply a copy of the letter for you; that does not mean the letter will be negative. If you do not believe the professor will write something favorable about you, you should not be asking him or her for this kind of letter.

If it has been a year or more since your last communication with the professor, help the professor remember you by explaining how you knew each other (professor for a course, department chair, advisor, etc.). Don’t expect a professor who does not know you or your work to write a letter of recommendation; that would reflects badly on the professor.