The most important methods for the determination of skeletal age according to Greulich and Pyle (1959) and Tanner et al. (1975) were tested for their applicability to West-German children. The validity of both methods was good with an intra- and interobserver error between 1,8 and 4,7 months. The practicability of both methods however was different, on average it takes 2--3 minutes for the Greulich-Pyle-inspection-method, whereas the Tanner-20-B-method required 8--9 minutes. The Tanner-20-B-method had to be corrected only for 6--10 years old girls, whereas the Greulich-Pyle-bone-specific-method required correction factors for all age groups from 2--16 years. Both, the Greulich-Pyle-and the Tanner-method can be recommended for use in West-Germany children when the described correction tables are applied. Also in children with abnormal growth both methods may be used without systemic error. However the cause of growth disturbance has to be taken into consideration for the individual case.