Precocious puberty constitutes a significant clinical problem due to psychological implications and health concerns as well as consequences associated with girls’ fertility. Selfacceptance, peer approval, early motherhood and future fertility – these are only a few issues associated with puberty, the disorders of which may have a negative influence on personality and health. The role of imaging is to determine the causes of early activation of the puberty process, to identify lesions responsible for abnormal sex hormone production and those which are the result of underlying hormonal disorders as well as to diagnose the processes which only mimic symptoms of precocious puberty. Out of all available imaging methods, sonography, thanks to its safety, availability and low cost, seems to be the best method to assess the breasts and internal organs of patients manifesting symptoms of precocious puberty both in early diagnosis and follow-up examinations. Apart from the technique of performing ultrasound examinations, the paper also explains its role in precocious puberty in girls, describes correct parameters of the organs which play the most significant role in the process of puberty as well as presents the features of changes responsible for or resulting from hormonal disorders.