HIV/AIDS is one of the sexually transmitted diseases that cause death worldwide. Its prevalence increases due to low prevention behaviour. The study aimed to estimate the effect of social capital on HIV/AIDS preventive efforts. This study was a meta-analysis and systematic analysis. We retrieved articles from PubMed, Science Direct, and Google Scholar from 2008–2021. The inclusion criteria were full-text articles with observational design and articles published in English. We focused on the problems of the PICO study, namely: population=men and women who were sexually active; intervention=high social capital; comparison=low social capital; outcome=HIV/AIDS prevention efforts. The articles were collected using the PRISMA flow diagram. Meta-analysis was performed using RevMan 5.3 with a random effect model. The study included 12 articles. The likelihood of sexually active men and women with high social capital to perform HIV/AIDS prevention efforts was 1.55 times higher than those with low social capital (aOR=1.55; CI 95%=1.11 to 2.16; p=0.009).