BACKGROUND AND OBJECTIVES: Since venous access in small children can be difficult to obtain, implantable venous access devices (IVAD) are used to administer clotting factor in such patients with severe hemophilia. The aim of our study was to evaluate how many children in our center needed an IVAD in order to be able to start early prophylaxis, what the differences were between children who needed an IVAD and those who did not and what the complications of the IVAD were. DESIGN AND METHODS: All 70 patients with severe hemophilia born between January 1987 and October 2000 treated at our center before they were 6 years old were studied. RESULTS: An IVAD was placed in 23 children (33%). Children with an IVAD started prophylactic treatment at a mean age of 2 years (SD 1.3), those without at a mean age of 3.6 years (SD 1.6) (p< 0.001). Home treatment was feasible at a mean age of 2.8 years (SD 1.3) in children with an IVAD and at 4.5 years in those without an IVAD (SD 1.8) (p = 0.001). Infection was the most frequent complication; the mean number of infections per IVAD was 0.61. Thrombosis was more common than initially thought (15%). The infection rate in children with inhibitory antibodies was 3.1 per 1000 patient-days; in children without an inhibitor it was 0.72 per 1000 patient-days. INTERPRETATION AND CONCLUSIONS: In 33% of the children in our cohort an IVAD was needed in order to start early prophylaxis. IVAD are needed more frequently when prophylaxis is started at an early age, but have the advantage that home treatment is feasible earlier. Infection is the most common complication, particularly in children with inhibitors.