Data on incidence, predisposing factors, enzyme clearance and effect of fasting are scant in ESRD children. We studied 14 episodes of acute pancreatitis (APE) in 8 ESRD patients (pts) in our Pediatric Dialysis Unit over the last 7 years (yrs). Total number of pts in the Unit were 36-42/yr. Their age was 14±7.4yrs [mean (M)±SD]. The primary renal disease was focal segmental glomerulosclerosis (3), renal hypoplasia (2), obstructive uropathy (1), lupus nephritis (1) and unknown (1). 10 APE occurred in pts on peritoneal dialysis (CCPD) with M dialysis duration (MDD) of 7.4 yrs and 4 in pts on hemodialysis (HD) with MDD 6.8 yrs. Three pts had recurrent (R) APE (M 3). On CCPD, AP was preceeded by staph. peritonitis in 2 pts and valproic acid intake in 1. Steroids and alcohol ingestion was present in 2 pts on HD. All APE presented with pain and vomiting; 1/3 had abdominal tenderness and dehydration; fever was infrequent. The M serum amylase (SA) initially was 467 IU/L (84-960) and lipase (SL) 2110 IU/L (200-7896). 13 APE had radiologic abnormalities (Abn) on ultrasound or CT. M hospital stay was 14 d (6-24). 12 APE required hyperal for a M of 5.5 d. Three pts had tumorous calcinosis (TC), two of them had R AP with hyperparathyroidism. Serum calcium x phosphorus product (CaxP) was 73.38 (40.8-111). H.pylori antibodies were (+) in 3. None had hyperlipidemia or liver dysfunction. One APE required transient insulin. Only 3 APE on CCPD had increased peritoneal fluid (PF) cell count; none had hemorrhagic fluid or positive culture. PF amylase was 5-100 IU/L(51±35). Amylase clearance (AC) was 0.24-1.02 ml/min(0.68±0.35). SL on HD was higher post dialysis (2607 ±3207) than pre dialysis (2110±2907) p<0.05. Most pts tolerated feedings after subsidence of symptoms in spite of raised enzymes. Decrease in SA and SL was slow over months. There was no mortality. Psuedopancreatic cyst developed in 2 pts, one required surgical intervention. Two pts developed chronic calcifying pancreatitis requiring enzyme supplements. A relatively high incidence of AP(0.05/Pt yr) was found among our ESRD pts, preferentially on CCPD. Elevated serum CaxP, TC, R AP, peritonitis and drug use were associated risk factors. AC did not increase markedly in APE on CCPD. Post HD, SL was significantly higher than pre dialysis, probably due to heparin use. Fasting did not induce a lower SA or SL. These data suggest that AP can be a serious complication of dialysis in children, that there are clear risk factors, and that some established measures may not be warranted.