A series of 325 patients with prostatic adenocarcinoma followed-up for over 13 years was subjected to histomorphometric analysis for the following prognostic factors: the Gleason score and 10 nuclear morphometric factors (mean nuclear area, nuclear perimeter, shortest and longest nuclear axis, form factor and their SDs), using the IBAS 1&2 image analyzer. Nuclear factors, Gleason score (P = 0.0013-0.0148), and T-category (P = 0.004-0.0107) were significantly interrelated, while the M-category was independent of the morphometric parameters. Nuclear factors (P = 0.0003-0.5), Gleason score (P < 0.0001), T-category (P < 0.0001) and M-category (P < 0.0001) predicted the disease outcome. In T1-2M0 tumors, the T-category (P = 0.0001), Gleason score (P < 0.0001), SD of nuclear area (P = 0.057), SD of nuclear perimetry (P = 0.039), mean shortest nuclear axis (P = 0.030), SD of the shortest nuclear axis (P = 0.0045), SD of the longest nuclear axis (P = 0.009), and nuclear form factor (P = 0.0123) were significant prognostic factors. In the multivariate survival analysis, the nuclear area had independent prognostic significance only in T1 tumors, whereas in other subcategories, the clinical stage, Gleason score, and patient age included all the available prognostic information. The results indicate that nuclear morphometric measurements are of borderline significance only in evaluating the intrinsic malignancy of prostatic adenocarcinoma.