The precision and accuracy of the Kerley and Ahlqvist-Damsten microscopic methods of age determination are compared. Both methods were applied to the same sample of 40 femoral thin sections of documented age at death. The results indicate that (1) both methods can be used with equal precision, as suggested by comparable observer errors; and (2) the Kerley method produces overall more accurate age estimates. The low previously published standard error of the Ahlqvist-Damsten method (6.71 years) apparently results from the uneven age distribution and small size (20) of their sample.