IntroductionPure androgen-secreting adrenocortical tumors are a rare but important cause of peripheral precocious puberty.Case presentationHere, we report a pure androgen-secreting adrenocortical tumor in a 2.5-year-old boy presenting with penile enlargement, pubic hair, frequent erections, and rapid linear growth. We confirmed the diagnosis through laboratory tests, medical imaging, and histology. Furthermore, genetic testing detected a pathogenic germline variant in theTP53gene, molecularly confirming underlying Li–Fraumeni syndrome.DiscussionOnly 15 well-documented cases of pure androgen-secreting adrenocortical tumors have been reported so far. No clinical or imaging signs were identified to differentiate adenomas from carcinomas, and no other cases of Li–Fraumeni syndrome were diagnosed in the four patients that underwent genetic testing. However, diagnosing Li–Fraumeni syndrome is important as it implies a need for intensive tumor surveillance and avoidance of ionizing radiation.ConclusionIn this article, we emphasize the need to screen forTP53gene variants in children with androgen-producing adrenal adenomas and report an association with arterial hypertension.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13256-023-03889-y.