Diagnosis of musculoskeletal tumors is quite often difficult and for the accurate diagnosis close collaboration of specialist in orthopaedic oncology, morphologist as well as roentgenologist is required. The more precise diagnosis of bone tumors can be made at specialized Centers (but not centers for general oncology) where roentgenologists and morphologists are trained for musculoskeletal tumors. Leading role in the collaboration of orthopaedic surgeon, roentgenologist and morphologist belongs to the clinician. These theses are confirmed by adduced clinical observations. The causes of diagnostic mistakes are analysed.