OBJECTIVE: To analyze age and condom use at first sexual intercourse among Brazilian adolescents at two periods: 1998 and 2005.

METHODS: Representative samples of the Brazilian urban population were interviewed during a household survey for two studies, carried out in 1998 and 2005. Interviewees included 670 sexually active young people (aged 16 to 19) who were selected for the study, 312 in 1998 and 358 in 2005. Pearson’s chi-square test and Fisher’s exact test (α< 5%) were used to analyze the weighted data.

RESULTS: In 2005, 61.6% of young interviewees had practiced sex and the average age for first intercourse was 14.9, with no significant difference to young interviewees in 1998. Condom use during first sexual intercourse increased significantly in both stable relationships (48.5% in 1998 vs. 67.7% in 2005) and casual relationships (47.2% in 1998 vs. 62.6% in 2005) across almost all segments. There were differences by gender, skin color and schooling for both age of first sexual intercourse and condom use, as per findings in 1998. Decreases in condom use for young people who were sexually active before the age of 14, across all types of partnerships, were marked in the Southeast region and for people with more schooling.

CONCLUSIONS: As in other countries, there was a trend towards the stabilizing of the age of first sexual intercourse for young people aged 15 to 19. The postponement of the first sexual intercourse is more frequent among youth with more years of schooling, a theme that should be discussed in the planning of sexual education and STI prevention initiatives for adolescents. In terms of reductions in vulnerability to HIV, the increase in condom use at first sexual intercourse is both relevant and significant.

DESCRIPTORS: Adolescent. Condoms, utilization. Sexual Behavior. Health Knowledge, Attitudes, Practice. Health Vulnerability. Population Studies in Public Health. Cross-sectional Studies. Brazil.