The attitudes of working females toward participating in a study of menstrual function were examined. The participants consisted of nine females, 25 to 34 years old, who had intact reproductive tracts and regular menstrual cyclicity. The subjects were instructed to measure basal body temperature and salivary (SER) and vaginal mucous electrical resistance, evaluate their cervical mucous manually, and collect the first morning urine daily for two complete menstrual cycles. Blood and saliva samples were collected for hormone analysis and transvaginal ultrasonography was performed every 6 to 9 days during each cycle at a clinic. The subjects kept a daily diary of what they did and their comments and observations. At the end of the study they completed a questionnaire to rate their willingness to perform the prescribed procedures and to evaluate the study. The subjects were paid 400 dollars for completing the study. A total of 193 nonparticipants had the study and the procedures explained to them and were then asked about their willingness to perform the procedures. The percentage of nonparticipants unwilling to perform the procedures after they were explained varied from 1 to 25%. The greatest degree of unwillingness was for giving blood samples and undergoing the transvaginal ultrasonic examination, 23 and 25%, respectively. All participants completed the study. The degree of compliance in performing the procedures ranged from 61 to 99%. The lowest compliance occurred for collecting blood and urine samples at the scheduled time. Half of the participants judged the ultrasonic examination as uncomfortable. Approximately 20% judged the manual cervical mucous evaluation and saliva collection for the SER to be uncomfortable. The only procedure the participants were reluctant to perform was the manual cervical mucous evaluation, 20% expressing unwillingness to do the procedure. All of the subjects rated the study as being important. Reasons for participating included making a contribution to science and society, and being paid. The authors conclude that working women selected from the general population can be willing compliant subjects for reproductive studies.