Introduction. Rhabdomyolysis is a potentially life threatening disease, characterized by the release of intracellular calcium from skeletal muscles and can result in acute renal failure. Case report. A nineteen year old boy was admitted to the Clinic for Infective Diseases of Clinical Center Novi Sad. The disease was developing gradually and the symptoms were dizziness, muscle pain and dark color of urine. Due to the pathological level of aminotransferase he was hospitalized on the fourth day of the disease beginning with a suspicious diagnosis of acute viral hepatitis. In the hospital course of the disease, a further elevation of serum aminotransferases, creatine kinase and lactate dehydrogenase were registered. Additional serological analyses were done to exclude other possible causes of acute liver lesion. In the neurological status prolonged decontraction of quadriceps muscle was detected and the electromyography was suspicious on neuromyositis. Conclusion. Excessive muscular activity with the strenuous exercise is the leading, but very frequently overlooked, cause of rhabdomyolysis in healthy people. Excessive physical exercise may lead to elevation of the serum activity of aminotransferases and to suspicion of hepatitis.