The current study focuses on factors associated with sexual initiation and condom use among teenagers on Santiago Island, Cape Verde, according to gender. This was a representative, probabilistic sample of 13-to-17-year-olds (n = 768) attending public secondary schools on Santiago Island in 2007. Associations were tested by test of proportion, Pearson's chi-square, or Fisher's exact test and logistic regression. Factors related to sexual initiation among boys were: age over 14 years, Catholic religion, and alcohol consumption. For girls, the factors included: > 9 years of schooling and involvement in an affective-sexual relationship. Unlike other Sub-Saharan countries, this study showed a high prevalence of condom use during initial sexual activity. Adolescents are able to safely begin sexually active life if they have access to information, sex education, and other STD prevention and contraceptive methods. This study provides insights on the development of policies to reduce the vulnerability of the young population to STD/AIDS and the limits and challenges related to the promotion of condom use and sex education, focusing on unequal gender relations.