The timing of cerebrospinal fluid shunt insertion for those neonates with hydrocephalus in association with myelomeningocele remains controversial. To examine whether there was a difference in either the complication rate or mean hospital stay for neonates undergoing myelomeningocele repair and shunting under the same anesthetic (simultaneous group) versus those in whom shunt insertion was delayed for several days after myelomeningocele closure (sequential group), we reviewed the results obtained with these two approaches in a series of 69 consecutive patients who underwent both myelomeningocele closure and shunt insertion at our institution between 1987 and 1993. Twenty-one infants underwent simultaneous myelomeningocele repair and shunting, and 48 underwent sequential procedures. The decision to shunt concurrently with myelomeningocele repair rather than in a delayed fashion was based primarily on surgeon preference rather than initial head circumference, which did not differ significantly between the two groups. The frequency and type of hydrocephalus-related complications (e.g., wound leak, cerebrospinal fluid infection, or shunt malfunction) that occurred during the first 6 months after myelomeningocele closure were compared between the two groups. Neither the overall frequency of complications nor the frequency of cerebrospinal fluid infection, shunt malfunction, or symptomatic Chiari malformation differed significantly between the two groups. In contrast, there was a significantly higher rate of myelomeningocele wound leak in the sequential group versus the simultaneous group (eight versus zero; P = .05). Mean hospital stay for the sequential group was also significantly longer than the simultaneous group (22 days versus 13 days; P = .05). These results suggest that simultaneous myelomeningocele repair and ventriculoperitoneal shunt insertion reduces hospital stay and back wound morbidity in those patients with evidence of hydrocephalus at birth, without an inordinate increase in shunt-related complications.