One of four commonly employed and apparently safe contrast media—80% Angio-Conray® (and later Conray 400®), 37% Renovist®, 50% Hypaque® and 60% Renografin®—was pre-assigned to each infant or child undergoing selective angiocardiography or thoracic aortography without regard to diagnosis, age or other factors. Analysis of 492 consecutive procedures showed no apparent differences in the type or frequency of complications associated with any of the above four contrast media.