Surgical splanchnicectomy for the relief of neoplastic pain is a palliative strategy in cases of unremovable pancreatic cancer. The first step in the achievement of satisfactory and long-lasting relief of pain is the correct identification of semilunar ganglia and splanchnic nerves during laparotomy. In this light, we tried to estimate the exact location, number, shape, and length of splanchnic nerves and ganglia in 15 corpses (mean age 39.9 years, range 21-74, F/M/ = 5/10). Right and left splanchnic nerves always pierce the diaphragm laterally to the crus. On the right side, the splanchnic nerve always enters the abdomen posterior to the inferior vena cava, on the right edge in 10%, on the middle in 73%, on the left in 17% of the cases. On the left side, the splanchnic nerve pierces the diaphragm strictly thickened to the left edge of the aorta in 66.6% of the cases, close to the left edge in 26.6%, and close to the right edge of the left adrenal gland in 6.8%. The right splanchnic nerve slides almost horizontally on the diaphragmatic bundles, and reaches an area delimited by the coeliac trunk and the superior mesenteric artery. The length of the right splanchnic nerve is 41 mm of the mean (range 20 to 55 mm): the thickness is between 4 and 6 mm. The left splanchnic nerve is shorter (mean 24 mm, range 15; 30 mm). The right splanchnic nerve varies from 2 to 6 ganglionar bodies and varies in size from 4.5 mm to 30 mm; the left nerve varies form 2 to 4 (sizes between 4 mm to 26 mm).(ABSTRACT TRUNCATED AT 250 WORDS)