LH-RH-, estrogen-, and progesterone-receptor binding was measured in the human pancreas of patients with ductal pancreatic cancer (n = 23) and chronic pancreatitis (n = 15), and of organ donors (n = 11). Receptor analysis was determined by incubation of the homogenized tissues with estrogen, progesterone, and the LH-RH analog buserelin labeled with iodine-125. Only one biopsy (9%) from normal pancreas had an LH-RH-receptor concentration greater than 3 fmol/mg membrane protein. LH-RH binding levels greater than 3 fmol/mg were detected in 67% of patients with chronic pancreatitis and in 57% of patients with pancreatic cancer. Progesterone levels greater than 15 fmol/mg membrane protein were found in 36% of normal pancreas, in 27% of chronic pancreatitis, and in 17% of pancreatic cancer cases, respectively. The highest concentration of estrogen receptors (greater than 15 fmol/mg membrane protein) was seen in normal pancreas (73%). The increase in LH-RH-receptor concentration in chronic pancreatitis and pancreatic cancer seems to be unspecific, but might be of benefit for antiproliferative treatment in pancreatic cancer.