For a pancreatic body or tail tumor, distal pancreatectomy with splenectomy (DPS) is a standard operation. Spleen-preserving distal pancreatectomy (SPDP) was introduced in order to preserve the organ and thus provide the patient with a better quality of life. Clinical data were compared between 38 Japanese patients with DPS and 9 with SPDP for benign tumors or tumor-like lesions at the body or tail of the pancreas at preoperative, early postoperative (< 3 months after operation), and late postoperative periods (>6 months after operation). The preoperative findings were not different between the two groups except for the significantly higher serum amylase levels in the SPDP group. Operation time, operative blood loss, and length of postoperative hospital stay were not different between the two groups. Pancreatic fistula occurred in 3 (8%) of the 38 patients in the DPS group and in 1 (11%) of the 9 patients in the SPDP group, abdominal abscess in 5 (13%) of the 38 patients in the DPS group and none (0%) in the 9 patients in the SPDP group. At short-term, clinical findings were not different between the two groups except for a significantly greater platelet count in the DPS group than in the SPDP group (46.8 x 10(4)/microl versus 29.6 x 10(4)/microl, P = 0.0081). At long-term after the operation, clinical findings, including the platelet count, were not different between the two groups. Computed tomography revealed a pseudocyst in 9 (53%) of 17 patients examined in the DPS group and in 3 (75%) of 4 patients examined in the SPDP group at short-term after operation. All patients with pseudocysts were asymptomatic. Two asymptomatic patients (one in the DPS group and one in the SPDP group) first developed a pseudocyst at long-term after the operation. The alteration of glucose tolerance was similar between the two groups. Postoperative pancreatic exocrine function (the N-benzol-L-tyrosyl-p-aminobenzoic acid test) was not different between the two groups. These data suggest that SPDP with preservation of the splenic vessels can be satisfactorily performed without elongating operative time and postoperative hospital stay or increasing risk of postoperative complications, with the exception of increased platelet count in the DPS group at short-term after the operation. Thus, SPDP is worth considering as one of the options for the treatment of benign lesions of the body or tail of the pancreas.