Using Cox's proportional hazard model and Weibull's proportional hazard model and taking into account the covariates involved, estimation of survival time was made on 94 confirmed deceased cases of unresectable pancreatic adenocarcinoma (excluding cases of cystadenocarcinoma) from the data of their admission for confirmation of diagnosis. The following results were obtained: 1) The covariates which were related to the prognosis of unresectable pancreatic adenocarcinoma were presence or absence of metastasis to the liver and lung, type of treatment for obstructive jaundice, and whether in such treatment, chemotherapy, or radiotherapy was conducted. 2) Estimation of the survival time after adjusting these factors showed that the median survival time was 57 days in untreated cases with metastasis, 107 days in untreated cases without metastasis, 284 days in cases with metastasis in which surgical treatment for obstructive jaundice, chemotherapy, and radiotherapy was administered, and 350 days in cases without metastasis in which the same positive treatment was administered. It can therefore be deduced that multidisciplinary treatment is effective in prolonging life.