Aggressive feeding practices are thought to increase the incidence of necrotizing enterocolitis (NEC). Detailed feeding histories of the 39 cases occurring between January 1, 1984 and May 31, 1985 were compared with matched controls. The study period included a cluster (epidemic) of 11 cases diagnosed within 1 month. Data were analyzed collectively and separately for endemic and epidemic cases. Collectively, cases had greater average daily intake volume, maximum daily intake volume, intake volume on the day prior to diagnosis, and maximum daily caloric intake (all p less than 0.05) than controls. The only recorded parameter that differed in endemic cases vs controls was intake the day prior to diagnosis. In contrast, epidemic cases were fed significantly more volume, more calories, and faster than controls: average intake volume (62.5 +/- 27.2 vs 37.4 +/- 18.0 ml/kg/day); maximum intake volume (118.5 +/- 33.5 vs 76.4 +/- 38.8 ml/kg/day); intake day prior to diagnosis (109.8 +/- 30.9 vs 63.8 +/- 43.1 ml/kg/day); maximum daily increment (42.6 +/- 16.7 vs 26.7 +/- 16.4 ml/kg); maximum caloric intake (126.1 +/- 44.6 vs 77.3 +/- 50.0) (all p less than 0.01). Five of the feeding parameters were significantly less for the epidemic controls than the endemic controls, suggesting a general slowing of feeding during the NEC epidemic. In summary, the data suggest feeding patterns may have an impact on NEC especially during epidemic periods.