The use of an Ommaya Capsule-Catheter System for the delivery of chemotherapy in cancer patients with inadequate peripheral veins has been studied over a 6-year period. Between 1978 and 1984, 76 Ommaya capsules were implanted in 68 patients, providing a collective experience of over 28,000 venous access days. Two patients were lost to follow-up. The results of the capsule-catheter system performance indicates a functional rate of over 90%. The complications included a 6.7% catheter occlusion rate, and a 2.7% capsule leakage rate. This accounts for an overall catheter related complication rate of 9.4%.