Circulating CEA levels were determined in 102 patients with histologically proven pancreatic carcinoma and 26 patients with chrdnic pancreatitis. In the group with pancreatic carcinoma eleven patients had resectable tumors, the mean CEA in the nonjaundiced patients was 10 ? 5 ng/ml while the mean value in jaundiced patients in this group was 27 f 40. Thirty-four patients with nonmetastatic locally unresectable disease had a mean serum CEA of 25 5 52 with a range of 1 to 250 ng/ml. Twenty-one percent had values of 5 ng/ml or less. The mean value in 57 patients with metastatic disease was 97 * 194 with a range of 0.5 to 1000 ng/ml and 19 percent had values of 5 ng/ml or less. Survival of patients with locally unresectable or metastatic carcinoma was significantly longer in those patients who had a normal CEA at the time of diagnosis. Circulating CEA in the metastatic group was much lower in patients with nonhepatic metastases as well as in those with well differentiated adenocarcinoma histology. Twenty-three patients with chronic pancreatitis and normal serum bilirubin had a mean CEA value of 5.3 f 4 ng/ml with 65% of values being 5 ng/ml or less but the CEA ranged from 4.6 to 27 in three who were jaundiced.