The nuclear DNA distribution pattern of the neoplastic parenchymal cells of 100 conventionally formalin-fixed and paraffin-embedded specimens from pancreatic adenocarcinomas and from 8 specimens of chronic pancreatitis was assessed by means of image cytometry. All material originated from pancreatic restrictions. Evaluable DNA histograms could be obtained for 77 carcinomas, and clinical data were available for 71 of these. In these 71 specimens, the nuclear DNA ploidy pattern was also investigated by means of flow cytometry. In 76 of the 77 cases, the image-cytometric DNA ploidy pattern obtained showed a "nondiploid" distribution with modal values as high as 8.5 c. In 21 cases, the neoplastic cells showed modal values in the "triploid" region. The analogous 71 flow-cytometric DNA histograms could only be evaluated in 50 cases because of excessively high amounts of background and/or excessively broad peaks. In 47 cases, the nuclear DNA histogram was nondiploid according to both techniques. The patients with carcinomas whose cell nuclei showed a triploid DNA distribution showed a significantly shorter survival time than those with tumor cell populations of nontriploid DNA distribution patterns. In the 8 specimens of chronic pancreatitis, the parenchymal cells were all equipped with nuclei showing diploid DNA distribution patterns.