Sexually transmitted diseases, including AIDS, and unplanned pregnancies continue to be a serious worldwide problem. A number of organizations are developing woman-controlled vaginal formulations to prevent these problems. However, little information is available regarding the types of products women prefer even though such knowledge is essential to obtain widespread use. This is the first of several articles that describe the results of a consumer preference study for such vaginal formulations performed in Campinas, São Paulo State, Brazil. Because no published methodology was available, the instruments and interview techniques were developed first and procedures established for the identification and participation of research subjects. After preparation of a questionnaire, a pilot study was performed to evaluate it, to establish the interview technique, and to determine the optimal method for subject recruitment. Based on the results, the approach was selected and applied to 635 subjects from different age and socioeconomic groups. The developed methodology and questionnaire, the advantages and the problems encountered, are presented.58233-8