A cross-validation study was conducted on the estimation of femoral condyle width from height and gender. An equation was published in 1989 for estimation of femoral condyle width using in vivo measurements of femoral condyle width from radiographs. Further cross-validation evidence for this equation is reported using in vitro measurements from 27 cadavers. The data indicated a high correlation (r = 0.85) between actual and estimated femoral condyle width and an acceptable standard error of estimate (range, 4.18–4.29 mm). It was concluded that the published equation which uses height and gender to form an estimate of femoral condyle width has acceptable validity and is a useful tool in the selection process of donors for osteochondral allografts.