To compare the effectiveness of cystgastrostomy and cystjejunostomy for treatment of pancreatic pseudocysts, 39 patients with cystgastrostomy were compared to 59 patients with cystjejunostomy. The groups were comparable in age, sex, cause of pancreatitis, pseudocyst location, symptoms, and preoperative serum amylase level. Cysts treated with cystgastrostomy were larger (mean diameter, 11.1 +/- 0.9 cm) than cysts treated by cystjejunostomy (mean diameter, 6.7 +/- 0.7 cm) (p less than 0.05). Mean duration of surgery was 148 +/- 11 minutes for cystgastrostomy versus 265 +/- 15 minutes for cystjejunostomy (p less than 0.05). Mean blood loss was 397 +/- 82 ml for cystgastrostomy versus 703 +/- 80 ml for cystjejunostomy (p less than 0.05) Mean intraoperative fluid requirements were 2640 +/- 313 ml for cystgastrostomy and 4403 +/- 362 ml for cystjejunostomy (p less than 0.05). Cyst recurrence was 10% for cystgastrostomy versus 7% for cystgastrostomy. Postoperative gastrointestinal bleeding occurred in 8% of patients with cystgastrostomy and in 2% of patients with cystjejunostomy. Infection problems with cystjejunostomy included two wound infections and one case of septicemia; infection problems with cystjejunostomy included five intraabdominal abscesses, two wound infections, and one case of pneumonia. Two patients died with cystgastrostomy (both from gastrointestinal bleeding); two patients died with cystjejunostomy (one from intraabdominal sepsis and one from pulmonary embolus). Cystgastrostomy was used for significantly larger pseudocysts and was associated with significantly less blood loss and operating time than cystjejunostomy (p less than 0.05). Morbidity and mortality from cystgastrostomy and cystjejunostomy were comparable, although gastrointestinal bleeding was more common with cystgastrostomy and intraabdominal abscess was more common with cystjejunostomy. Since cystgastrostomy can usually be performed more quickly and with less blood loss, it should be considered whenever anatomically feasible.