In this paper we investigate a particular type of stress marking in Czech, in which the syllable perceived as prominent is not accompanied by any clearly audible change in the overall pitch course. The paper gives a perceptual, phonotactic and acoustic account of these “flat pitch accents”. No positional effects or semantic correlates of words bearing this type of accent were found. Flat accents have significantly reduced intonational variability, as expected, and their durational and dynamic correlates are partly different from other accent types. However, none of these findings speaks in favour of compensation between prosodic parameters.