To assess the changing role of cardiac catheterization in the care of the neonate, a retrospective review of all catheterizations between January 1984 to December 1985 (group I) and January 1994 to December 1995 (group II) at C.S. Mott Children's Hospital was performed. Neonatal cardiac catheterization was performed more frequently (p = 0.02) in group I, comprising 14% (110 of 772) of all catheterizations versus 11% (93 of 880) in group II. Access was performed by cutdown in 15 patients (13 venous and 2 arterial), all in group I. In group I, 20 of 110 patients (18%) had balloon atrial septostomies; no other catheter interventions were performed. Interventions were more frequent (p = 0.003) and varied in group II, including 15 septostomies, 17 balloon valvuloplasties (13 pulmonary and 4 aortic), 2 coil embolizations of collaterals, and 1 cardiac biopsy. Despite the higher prevalence and complexity of interventions in group II, fluoroscopy times (median; range: 16 min; 2-55 vs 16 min; 1-107) were similar in both groups (p = not significant) as well as the prevalence of complications. Neonatal cardiac catheterizations are performed less frequently than they were a decade ago at our institution, and therapeutic interventions have become more common. Despite these changes, fluoroscopy time and the rate of complications have not increased.