If you've got the blocking type stutter it may make sense to mention it at the beginning of the interview; perhaps something lighthearted yet helpful. I recently had a phone interview where I had terrible fluency. Funny thing is I got called for a follow up interview in person, and I got the feeling that the 2nd interview guys thought I was moron. The piss of it is you really can't know if it was because of my speech, if it related to my mediocre college education, if the typo on my resume automatically made this guy think I was incompetent, if he didn't understand how my current position was related to the position I was applying for, or if I'm just being paranoid and he never even though I was an idiot at all. I don't think that my stutter has prevented me from getting any jobs, but now that I think about it there may have been one or two situations where I applied for something internally, was familiar with the interviewer, and felt that I was immediately written off. Again, do they assume that I'm of below average intelligence because I stutter, did someone say something unflattering behind my back some months ago that stuck with this person, or do they already have someone in mind for the job and the interview is more of an HR formality? In most cases you won't ever know, so I typically just assume the best unless I have a good reason not to. In my 20s I spent too much time rehashing conversations in my head, analyzing missed opportunities, and honestly, feeling sorry for myself to some extent ("if only I didn't have this speech problem I'd be a great stand up comedian...even though I never put any time into it"). These days I don't give my speech much thought which I believe has helped my speech.