We describe here the results of our analysis of the comparative modeling predictions submitted to the fourth round of Critical Assessment of Structure Prediction (CASP4). On the basis of a numerical evaluation of the models, we assessed their ability to predict the overall fold correctly, the relative orientation of domains in multidomain proteins, the conformation of the side chains, the loop regions, and the biologically important residues of the targets. We also discuss the performance of automatic prediction servers and compare the results of CASP4 with those obtained in CASP3. Proteins 2001;Suppl 5:22–38. © 2002 Wiley-Liss, Inc.