295 patients subjected to screw osteosynthesis for closed oblique and screw-shape fractures of crural, brachial and antebrachial bones were under observation. The use of screws of a cylindrical form with a somewhat conus-like head and deep slit seems to be most rational for osteosynthesis. To apply screws properly two drills should be available. One should be equal to the diameter of a screw, the other-0.5 mm less. Following screw ostenosynthesis an adequate plaster dressing is applied for 2-3 months. The results of the treatment were good in 280 patients (95%) and poor-in 15 patients (5%). The causes of failure were as follows: improper indications to screw osteosynthesis, an early cessation of immobilization of an extremity in a plaster dressing, and too early loading on the extremity.