Background:The relationship between HIV risk perception and consistency in the use of condoms is scarcely understood in the context of a high HIV prevalence among adolescents and young adults in urban South Africa. Methods: Using data from Cape Area Panel Study (CAPS), gender-stratified analyses were conducted to determine relationship between risk perception and condom use among 14-22 year olds (n = 4 853) in urban Cape Town. Using discriminant function analyses, ecological determinants of consistency in condom use were determined and a cumulative risk approach examined. Results: A total of 1 598 sexually active youths, of mean age 17.7 years, with 785 (49%) of males and 813 (51%) females were identified for analyses. At baseline, 87% of males and 90% of females assessed themselves to be at no or low risk of HIV infection. At follow-up, 61% of males reporting low or no risk were consistently using condoms compared to 67% reporting some risk of HIV infection. In females, 47% reporting low or no risk consistently used condoms compared to 49% of those reporting to be at some risk. Conclusions: Perceived risk for HIV infection had no significant impact on consistency in using condoms for both males and females. Further, findings suggests that the effect of ecological risk factors was cumulative. Therefore, interventions aimed at the three levels ecology may be more effective in improving consistency as risk factors possess a cumulative effect.