Gynecomastia is benign hypertrophy of male breast glandular tissue, either unilateral or bilateral, secondary to increased estrogen/testosterone ratio (elevated estrogen level, decreased testosterone levels, or both). The condition can be related to a medical disease or caused by some drugs.Since the introduction of triple antiretroviral therapy (TAT), we have seen an improvement in the prognosis of human immunodeficiency virus (HIV) infection.Here we report the case of a 53-year-old man receiving follow-up care in Internal Medicine for HIV infection receiving TAT (tenofovir/efavirenz/emtricitabine). After one year, the patient presented in the Department of Endocrinology, Diabetology, Metabolic Diseases, and Nutrition of Hassan II University Hospital Center, Fez, with bilateral gynecomastia. Hormonal exploration did not reveal any abnormality, so the gynecomastia was attributed to efavirenz use. The regimen was replaced by tenofovir, lamivudine, and dolutegravir. The gynecomastia was resolved within two months of discontinuing efavirenz.In summary, we think that secondary gynecomastia should be suspected and screened in HIV patients receiving efavirenz-containing regimens.