Precocious puberty in boys is defined as the onset of puberty before the age of 9 years. It is divided into two categories: central precocious puberty, characterized by the premature activation of the hypothalamic-pituitary-gonadal axis, and peripheral precocious puberty presents when premature sexual development is dependent on steroid production regardless of gonadotropin secretion. Although precocious puberty occurs more frequently in girls, in the case of boys it is more often associated with identifiable organic disorders of the central nervous system, adrenal glands or testes. The diagnosis should include detailed anamnesis and clinical examination, measurement of pituitary and sex hormones, assessment of bone age, and imaging of the hypothalamus, pituitary gland, adrenal glands and testes. Indications for treatment are based on the type of precocious puberty and its progression rate, advancement of bone age, predicted adult height and psychological evaluation. The purpose of this article was to discuss the etiopathogenesis of precocious puberty in boys and to provide the approach to its diagnosis, differentiation and treatment.