Sexual development in children due to exogenous androgen exposure is rare and sparsely reported. In this paper, we present a new case of peripheral precocious puberty of exogenous origin in an 18-month-old boy due to inadvertent exposure to a testosterone gel used by his father as hormonal replacement therapy. We also review other cases in the literature. Most of these cases are due to a secondary exposure to androgen topical preparations, such as gels or creams. We highlight the value of the knowledge of the existence of these preparations to the paediatrician, given the increasingly widespread use and production of adverse effects from inadvertent contact, especially in children.