Among the many psychometric measures of sexual (dys)function, none is entirely suited to use in community surveys. Faced with the need to include a brief and non-intrusive measure of sexual function in a general population survey, a new measure was developed. Findings from qualitative research with men and women in the community designed to inform the conceptual framework for this measure are presented. Thirty-two semi-structured interviews with individuals recruited from a general practice, an HIV/AIDS charity, and a sexual problems clinic were conducted. From their accounts, 31 potential criteria of a functional sex life were identified. Using evidence from qualitative data and the existing literature, and applying a set of decision rules, the list was reduced to 13 (eight for those not in a relationship), and a further eight criteria were added to enable individuals to self-rate their level of function and indicate the severity of difficulties. These criteria constitute a conceptual framework that is grounded in participant perceptions; is relevant to all, regardless of sexual experience or orientation; provides opportunity to state the degree of associated distress; and incorporates relational, psychological, and physiological aspects. It provides the conceptual basis for a concise and acceptable measure of sexual function.