In Brazil, the effectiveness of preventive public heath programs and actions is rarely evaluated. A cross-sectional study was thus performed in a population-based sample focused on several health characteristics of adults living in Pelotas, Rio Grande do Sul, Brazil. The study aimed to measure temporal trends in coverage of Pap smear testing in the city. The authors studied the factors associated with failure of women to submit to a Pap smear. An updated Pap smear was defined as one performed in the previous 3 years. The sample consisted of 1,122 women ages 20 to 69 years, 72.2% of whom had an updated Pap smear, 16.6% of whom were behind schedule for testing, and 11.2% of whom had never had a Pap smear. Risk factors for never having a test were low socioeconomic status and old age. Logistic regression showed an independent effect of social class, low family income, age, skin color, marital status, and no medical appointment in the previous year. However, the effect of chronic diseases disappeared in logistic regression. The authors compare the results of the study conducted in 1992 with the present. Pap smear coverage increased from 65.0% to 72.2% (1992 to 1999/2000) in the city, yet such figures had still not ensured the effectiveness of the program for uterine cervical cancer prevention.