When a word is focused in some context in Japanese, its fundamental frequency (f0) range is usually increased [Pierrehumbert and Beckman (1988)]. It is also well known that Japanese females tend to employ higher frequencies when they speak in Japanese than Caucasian females do [Yamazawa and Hollien (1990)]. However, previous studies have not examined the interactions between these two factors, focus and gender. The present study was done to determine whether the same strategy for realizing focus is employed by female and male speakers, in terms of the f0 and temporal patterns. From the analysis of 252 utterances produced by six Japanese speakers, almost the same amount of increase in absolute f0 values was observed in the speech of both sexes. Therefore, when viewed in proportion to the speakers’ normal f0 range, females showed smaller increases in the proportional f0 values on the focused words than males did. The results suggest that Japanese females have less room for focus expansion because they normally use higher frequencies within their pitch range. Since temporal focus effects do not occur in female speech, it is considered that the perception of intended words as emphasized will be more ambiguous in female than in male speech.