Clinical symptoms of bone tumour are non-specific. The first symptom inclining to take medical advice is pain, alleged injury and fracture. Other symptoms e.g. change of temper and behaviour of the child, radiculalgia, pareses and paralyses, depend on location of primary focus. There are also cases, which are accompanied by temperature, cough and infection of urinary tract. Demonstration of pathologic focus on RTG image begins diagnosis of bone tumour. Still very often, time that passes away from the moment of taking the first radiogram is differently long. Begin tumours in majority grow asymptomatically; often they are detected accidentally while taking radiograms because of other reasons. Fast growth is one of the characteristics of malignant neoplasm. Characteristic features distinguishing between begin tumour and malignant neoplasm on RTG images and diagnostic value of images obtained in CT and MR studies are presented, remembering that final diagnosis of bone tumour is based on histopathological examination.