Nonfunctioning pancreatic endocrine tumor (NFPET) is a kind of tumor with high malignancy but bland in morphological features. It is impossible to predict the malignancy solely by gross and light microscopic pictures of the tumor. For the purpose of assessing the value of flow cytometry and morphometry in predicting the prognosis of NFPET, the DNA content and several morphological parameters of 26 NFPETs were determined by appropriate techniques. The results show that abnormal DNA content has no practical value in discriminating benign from malignant NFPETs; whereas the "score" obtained by combining the morphological measurements of the number of nuclei/mm2 and N/C, is of certain referential significance in predicting the malignancy of NFPET.