Purpose: We investigated cross-linguistic differences in fundamental frequency range (FFR) in Welsh-English bilingual speech. This is the first study that reports gender-specific behavior in switching FFRs across languages in bilingual speech. Method: FFR was conceptualized as a behavioral pattern using measures of span (range of fundamental frequency--in semitones--covered by the speaker's voice) and level (overall height of fundamental frequency maxima, minima, and means of speaker's voice) in each language. Results: FFR measures were taken from recordings of 30 Welsh-English bilinguals (14 women and 16 men), who read 70 semantically matched sentences, 35 in each language. Comparisons were made within speakers across languages, separately in male and female speech. Language background and language use information was elicited for qualitative analysis of extralinguistic factors that might affect the FFR. Conclusions: Cross-linguistic differences in FFR were found to be consistent across female bilinguals but random across male bilinguals. Most female bilinguals showed distinct FFRs for each language. Most male bilinguals, however, were found not to change their FFR when switching languages. Those who did change used different strategies than women when differentiating FFRs between languages. Detected cross-linguistic differences in FFR can be explained by sociocultural factors. Therefore, sociolinguistic factors are to be taken into account in any further study of language-specific pitch setting and cross-linguistic differences in FFR.