Ploidy was studied with flow and image cytometry in 51 polyps removed endoscopically from 44 patients. Evaluation was carried out on frozen material in 34 cases and on material fixed in formalin and embedded in paraffin in the remaining 17. Data analysis showed a statistically significant correlation between polyp size and aneuploidy frequency (P > 0.05). No statistically significant correlation was found between aneuploidy frequency and histological type. The linear correlation study did, however, show a correlation tendency between histological type and aneuploidy (R = 0.42211).