Many studies document the disproportionately high attrition rate of women in science, especially at early points in their careers. This ethnographic and conversational analytical study of a university life sciences laboratory group goes beneath statistical findings to explore one reason often cited by women who have dropped out of science: a `bad lab experience'. A detailed analysis of the interactional patterns or culture of the laboratory group suggests that discursive practices reinforce a conflation of gender, culture, and authority creating a climate that may be experienced as `chilly', or even `hostile', by some female members.