The increasing long-term use of intravenous chemotherapy has resulted in problems of venous access for a number of reasons, one being the sclerosing action of the drugs used. Silastic catheters were introduced to ameliorate this problem, initially with some caution because of potential complications and the lack of necessary equipment. The purpose of this paper was to show that the procedure is simple, effective and associated with few complications. Ninety-six patients (32 men, 64 women) with lymphoma (25), leukemia (28), metastatic breast cancer (28) or other malignant lesions (15) were referred for insertion of a Silastic permanent indwelling catheter into the superior vena cava. The catheter was inserted through a subclavian vein using a Cordis Vein Dilator Kit, itself introduced over a guide wire inserted initially under fluoroscopic control. Local sepsis at the insertion site occurred in 6 of the first 43 patients treated but in none of the remainder. Six catheters became thrombosed and required revision. There were no instances of bleeding, air embolism or pulmonary complications. Patient acceptance of this method of venous access was high compared with that for peripheral, repeated venepuncture.