The authors report a series of controlled comparisons of fifty-eight one-to-one qualitative interviews and thirty-seven mixed-sex joint interviews on the same health-related topics. Their analysis identifies comparative keyword frequencies and is supported by qualitative investigations of keywords in context, drawing on existing relevant knowledge of common gender differences in language choice. Gender differences are reduced and women's perspectives are more prominent in joint interviews, so researchers wanting to find out about men's experiences concerning health-related topics such as those associated with fatherhood may find out more in one-to-one interviews with men. The greater readiness of men to engage in gender-stereotyped behavior in sole interviews, most of which involved a female interviewer, suggests that an interviewer's gender identity is perceived as somewhat neutral by comparison with the considerable salience of the gender of a joint respondent. This finding potentially contributes to knowledge of the qualitative interview as a special form of institutional talk. © 2008 Sage Publications.