Undergrad CV – listing posters you presented but did not author There seems to be a bias, particularly among more established researchers, to only include posters that they presented. There seems to be a trend towards not including (or including as abstract accepted) posters where they are listed as an author, but someone else presented. 

My question is the reverse of that: If you were not involved in the project (thus no authorship), but presented the poster at a conference, would you include that on your CV?

Example: I attended a conference this year; my PI was supposed to present two of their posters, but couldn’t make it at the last minute. We’re currently working on extensions of that research, so I was familiar with the topic, but I wasn’t involved in those particular projects. I was also presenting at that conference, and so I presented my PI’s posters as well.

Is it acceptable to include those on my CV, with a note about “presented by [self] at [event]”?
Yes, it is acceptable. However, I would not list it in my "publication section", rather in a separate section called "Paper/Poster Presentations".

If you received any certificate (or letter) after the presentation, then that is a plus.