Peripheral and central intravenous injections of contrast material were performed during the cardiac digital subtraction angiographic (DSA) studies of 24 patients keeping constant X-ray exposure factors, volume of dye, and angiographic projection. The resulting continuous-mask-subtracted runs of cardiac images were videotaped and reviewed by three observers. In a forced-choice comparison, the central injection was judged to produce images of superior technical quality 42 times as opposed to 30 times for the peripheral injection. When comparing the diagnostic quality of the studies, the reviewers found no significant difference in diagnostic adequacy in 65 judgments (90%). They found the central injection to be superior in diagnostic quality in four judgments (twice in the same patient) and the peripheral injection superior in three judgments (all in the same patient). Although central intravenous injections produce slightly better cardiac digital subtraction angiographic images, we have found peripheral injections diagnostically adequate for most of these studies and favor them for simplicity and ease of performance.