Objectives To describe the presentation and progress over the first year of life of neonates with Hirschsprung disease, to describe their physical and developmental outcomes at 12 months of age, and to compare the outcomes of infants with short- vs long-segment Hirschsprung disease. Study design A retrospective study of neonates born with Hirschsprung disease in Western Australia between January 1, 2001, and December 31, 2010, to review their presentation, progress, growth, and development at 12 months of age. Results Fifty-four infants were identified (40 with short and 11 with long segment and 3 with total colonic aganglionosis); 9 infants had a recognized syndrome and 1 infant died, unrelated to Hirschsprung disease. A primary pull-through procedure was performed in 97% and 21% of neonates with short- and non-short-segment Hirschsprung disease, respectively; 17 (31%) infants developed anal stenosis requiring dilatations. Enterocolitis occurred in 14 (26%) infants. Griffiths Mental Development Scale scores (1 year) were available in 31 of 45 nonsyndromic survivors: mean general quotient (94.2, SD 8.89) was significantly less than the population mean (P =.007), but the number of infants with developmental delay was within the expected range. Physical growth, except length, appeared adequate in nonsyndromic infants. There were no significant differences in the outcomes of infants with short- vs non-short-segment Hirschsprung disease. Conclusions At 1 year of age, many infants with Hirschsprung disease have ongoing gastrointestinal problems. Their overall growth appears satisfactory, and most infants are developing normally; however, their mean general quotient appears shifted to the left. Longer-term studies will better define developmental outcomes. © 2014 Elsevier Inc. All rights reserved.