The use of drugs such as Viagra to treat sexual dysfunction in women may be beneficial in a proportion of cases. However, there are a number of barriers to understanding and predicting which women are likely to benefit, and caution is required in approaching this clinical issue. Three relevant issues are discussed: (1) Male-female differences in sexuality. Three complimentary ways in which male and female sexuality differs are considered--women have less need for their sexuality to be influenced by reproductive hormones; their needs for sexual enjoyment and orgasm are not well met by conventional vaginal intercourse; and, as a result of the disjunction between female sexual response and reproduction and a possibly greater propensity for central inhibition of sexual response, women are more susceptible to the repressive effects of social constraints on sexuality; (2) Sex therapy. While conventional forms of sex therapy are well designed to address the particular psychological needs of women as well as men, the interface between psychological processes and physiological response is not well understood. For the same reason, we should expect difficulty in predicting when pharmacological effects on sexual response will be beneficial; (3) When is a sexual problem a sexual dysfunction? It is likely that many cases of impaired sexual response or interest in women are psychologically understandable and hence adaptive reactions to problems in the sexual relationship, and hence not dysfunctions. Until we can distinguish between such adaptive inhibitions of response and those that are maladaptive dysfunctions, we will have difficulty in predicting when pharmacological treatment will be helpful.