In this article the authors argue that claims of sex differences in interruption behavior should not be uncritically accepted as there are limitations in previous research that make such acceptance questionable. The frequency of interruption was examined over a portion of the early life span (Grades 4 and 9 and college). Twenty-minute structured conversations of 90 dyads (30 male, 30 female, and 30 mixed sex) were scored for four types of interruption, and both developmental and sex differences in interruption behavior were examined. Interruption frequency did not change over age or across dyads of different sex composition. Males did not interrupt any more than females did and females were interrupted by their partners as frequently as males were interrupted by theirs, with one exception: Grade 9females were interrupted more by their female partners. Interruptions were asymmetrically distributed in same-sex and opposite-sex dyads; however, the asymmetry in opposite-sex dyads was not predictablefrom sex of subject or sex of partner. That is, males did not interrupt females any more than females interrupted males. The authors conclude that wholesale acceptance of sex differences in interruption behavior is not warranted.