b＞Introduction/b＞: Megacystis microcolon intestinal hypoperistalsi ssyndrome(MMIHS) is a rare congenital anomaly that presents with a functional obstruction of the gastrointestinal tract in neonates. It is characterized by abdominal distension, bladder distension, microcolon, hypoperistalsis. This syndrome usually presents in females and is an autosomal recessive disorder. We present the case of a premature male infant presenting with all the above criteria for MMIHS who was perinatally giant bladder. b＞Case report/b＞: The male patient was born at a geastation ageof 32 weeks by caesarean section. Fetal ultrasonography demonstrated hydronephrosis and giant bladder by since 16 weeks of gestation. Fetal bladder centesis was performed on nine occasionsby the obstetrician spanning the entire gestation period. We implanted an urinary catheter to resolve sustained urinary obstruction. After birth, no meconium was noted and bowel sound could not be heard. On hospitalization day (HD) 12, we performedan upper gastrointestinal series using gastrograffin. However the contrast media did not advance to the large bowel and bowel sounds were still not heard by ausculatation. A gastrograffin enema was performed on HD 20. This study evidences microcolon On HD 30 we chose to perform an exploratory laparotomy and wedge resection of the terminal ileum and the bladder. During surgery, we did not observe peristalsis andthe bladder dilatated despite indwelling of a Foley catheter. Biopsy was performedwhich indicated decreased smooth muscle actin expression of both the ileum and bladder. b＞Conclusion/b＞: We present the case of a male premature infant diagnosed with MMIHS associated with perinatally giant bladder.