Background: Verbal perseveration (i.e. excessive self-repetition) is a characteristic of male individuals with fragile X syndrome; however, little is known about its occurrence among females or its underlying causes. This project examined the relationship between perseveration and (1) gender, (2) cognitive and linguistic ability, and (3) language sampling context, among youth with fragile X syndrome. Method: Language transcripts were obtained from adolescent male (n = 16) and female participants (n = 8) with fragile X syndrome in two language contexts (i.e. narration and conversation) designed to elicit spontaneous language samples. Transcripts were coded for utterance-level repetition (i.e. repetition of words, phrases, dependent clauses or whole utterances), topic repetition and conversational device repetition (i.e. repetition of rote phrases or expressions). Results: Male participants produced more conversational device repetition than did female participants. Gender differences in conversational device repetition were not explained by differences in non-verbal cognitive or expressive language ability. Context influenced the type of repetition observed; for example, more topic repetition occurred in conversation than in narration regardless of gender. Conclusions: The observed gender differences in conversational device repetition among adolescents with fragile X syndrome suggest that, relative to females, male participants may rely more heavily on rote phrases or expressions in their expressive language. Further, results suggest that this gender difference is not simply the result of the correlation between gender and cognitive or linguistic ability in fragile X syndrome; rather, gender may make an independent contribution to conversational device repetition. Repetition type also varied as a function of expressive language context, suggesting the importance of assessing language characteristics in multiple contexts.