The gross features of prostatic adenocarcinoma can be subtle. While these gross features have been described, the histologic correlates have not been detailed. This study involved examination of 211 consecutive radical prostatectomy specimens between January 1995 and December 1996. The gross findings were correlated with histologic examination. No gross lesion was apparent in 47 cases (22.3%), a subtle lesion was present in 78 (37.0%), and a definite lesion suggestive of carcinoma, in 86 (40.8%). Tumor was identified grossly and confirmed histologically in 50 (64%) of 78 subtle lesions, 83 (96%) of 86 definite lesions, and in 63% of all prostatectomy specimens. Prostatectomy specimens with definite lesions were significantly more likely to contain tumors that were stage T3 or higher (37%) than those with a subtle lesion (20%), were higher grade (mean Gleason score, 6.8 vs 6.36), and had larger tumor diameters (mean, 1.3 cm vs 1.0 cm). Specimens with subtle lesions were more likely to contain tumors that were stage T3 or higher compared with specimens with no apparent gross lesions (20% vs 4%), but did not differ significantly in mean Gleason score (6.36 vs 6.26) or tumor size (1.0 cm vs 0.95 cm). Ninety-two percent of all tumors stage T3 or higher, 81% of all tumors Gleason score 8 or higher, and 72% of all tumors greater than 1.0 cm in diameter were grossly identified and confirmed histologically. However, the site of extraprostatic extension and positive margins were present in the histologic sample of the grossly identified lesion in only 27 (54%) of 50 cases and 20 (46%) of 43 cases, respectively. Prostatic adenocarcinomas can be accurately identified by gross inspection in 63% of cases; the false-positive rate for gross inspection was 19%. The presence of an identifiable gross lesion is correlated with increased tumor stage, grade, and size.