Acute hematogenous osteomyelitis is one of the common bacterial infections in children of early age, which is accompanied by mild symptoms at the initial stage of diagnosis. The onset of the disease is usually acute with fever, intoxication syndrome, focal signs of bone inflammation and limitation of limb function. Purpose - to show the features of diagnosis and treatment of acute hematogenous osteomyelitis in an infant based on clinical observation. Clinical case. The clinical case of a child of early age with acute hematogenous osteomyelitis, who was hospitalized with complaints of an increase in body temperature up to 40°C, restlessness, swelling and hyperemia of the lower part of the right thigh and right knee joint, and movement disorders in the right leg, was presented. The general condition of the child upon admission is severe due to intoxication, hyperthermic syndromes and local changes in the right lower limb, which was in a forced position, pronation. There were no active movements in the right leg, passives ones were painful. Rotational movements in the right leg are possible, but painful. The soft tissues in the area of the right hip and knee joints, as well as the thighs, were not changed in color, their swelling was noted. Conclusions. Symptoms of acute hematogenous osteomyelitis in young children are often nonspecific. Intoxication syndrome symptoms and local changes as movement disorders in the limb in children of this age group dominate. Pain can be detected during the examination, which is clearly localized with sensitivity over the infected bone; edema may be present. Changes of complete blood count are mild, while the determination of C-reactive protein during the initial evaluation can serve as a baseline value for sequential monitoring. The sensitivity of X-ray examination at the beginning of the disease is low, radiological changes appear only 7-21 days after infection. Empiric antimicrobial therapy aimed at Staphylococcus aureus should be prescribed immediately after the detection of acute hematogenous osteomyelitis clinical signs even before receiving results of additional research methods. The research was carried out in accordance with the principles of the Helsinki Declaration. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.