Histologic slides were reviewed from 192 autopsies of patients with non‐Hodgkin's lymphomas admitted to the National Cancer Institute (NCI) from 1953 to 1975. Each autopsy was classified according to the systems of Rappaport and Lukes‐Collins. Comparisons with the initial diagnosis were made. The initial histologic diagnoses of the autopsied population were similar in distribution to other published series of non‐Hodgkin's lymphomas. Of the 56 cases which initially demonstrated nodular patterns of growth, the following distribution was found at autopsy: 25%, no lymphoma; 6%, nodular lymphoma; 32%, diffuse histiocytic (large cell) lymphoma (DHL); 21%, diffuse undifferentiated (non‐Burkitt's) lymphoma (DUL); and 16%, the remaining diffuse morphologies. Of the 136 patients with initial diagnosis of diffuse lymphoma, the following distributions were observed at autopsy: 20%, no lymphoma; 0%, nodular lymphoma; 31%, diffuse histiocytic (large cell) lymphoma; 12%, diffuse undifferentiated (non‐Burkitt's) lymphoma; 9%, Burkitt's tumor; 14%, diffuse poorly differentiated lymphocytic lymphoma; and 14%, the remaining diffuse morphologic types. One hundred and thirty‐four cases which were initially diagnosed as follicular center cell type within the Lukes‐Collins classification gave the following distribution at autopsy: 21%, no lymphoma; 25%, small noncleaved type; 17%, large non‐cleaved type; 23%, non‐follicular center cell lymphomas (17% immunoblastic B); and the remaining 13% were distributed among the other follicular center cell types. This autopsy review demonstrates the rarity of nodular (follicular) lymphomas at autopsy, and the predominance of the diffuse histiocytic or “transformed” type. This study provides a comparison of the rate of histologic progression of lymphomas in the same patient population at autopsy with a previously published study of progression during life.