I guess it would be relevant to note that I'm female.

I posted about a similar dilemma, in case you want historical opinions. :-)

It was for a paid position, however, and I did not end up getting the job, so take all that with a grain of salt!

Somewhere in between seems about right - a cut above "smart casual" and fairly conservative.

I agree. Dressing a little better than necessary will show you are impressed by/respect their organization.

It occurs to me that they actually canceled the second interview on me (they hired someone else in the meantime), so I can confidently say that my sartorial choices played no role in my not getting hired. (Plus, I ended up with a much better job.)

I work at a nonprofit and we hire volunteers all the time. Looking back, all the ones we've wound up hiring dressed as if interviewing for a professional, paid position, even though the interviewers were dressed pretty casually. I say dress professionally, and impress them with how seriously you view the position -- there'll be time to dress down (starting probably with your second day on the job).

Caveat - the nonprofit I work at is a legal services organization. It may very well be that lawyers don't know how to dress down for an interview -- it's one of the things they beat into us in law school I think.

For my first volunteer interview, I decided what the hell, I'd wear my best business suit and accessories. Of course when I got there, all the staff and the facility manager were wearing street casual.

While I talked to the manager, the state director of the charity stopped by after having lunch with the mayor. She was, of course, dressed to the nines.

When she heard I was interviewing for the media relations position (unpaid), she handed me a notepad and said, "Here are my notes. Email me some copy by noon tomorrow." That was the extent of my interview; they never even looked at my writing samples.

It probably won't hurt to dress up but personally I can never bring myself to wear a suit to volunteer interviews. I go with slacks/khakis, non-sneaker closed toe shoes, button down shirt and a thin cotton vest to go over that. I guess that would be business casual to some people. :)

I'm another longtime nonprofit worker, and I agree with the "nicer than casual, but not necessarily full-on professional" suggestion.

For posterity's sake: I went with a cropped black jacket, v-neck red shell, black boot-cut slacks, and dressy boots. The guy didn't seem to care at all (he was wearing a suit, oddly, but I got the impression he was meeting a donor later). I think he was just thrilled to have someone taking on a project that has languished for years.

Yay! Glad it worked out. And that outfit sounds both stylish and perfect. I want one.

Sadly, I bought the pants in Paris (at a store called La Cité), so I won't be getting more anytime soon.