Testotoxicosis arises from testicular autoactivation due to LH receptor activating mutations and is a cause of falsegonadotropin-independent precocious puberty. A male child aged 2 years and 3 months was admitted to our clinic withpubic hair in the genital area. He had a family history of precocious puberty in the father and the father s male cousins.On physical examination skin and systemic findings were normal, bilateral testis volume was 4 ml, stretched penilelength was 4.5 cm, and pubic hair was Tanner stage 2. Although the testosterone levels were pubertal, baseline andstimulated LH levels were prepubertal.The patient was diagnosed with testotoxicosis with the family history, and clinicaland biochemical evaluation.The case was presented because of its rarity.