With current 2-dimensional echocardiography (ECHO) and colour-flow Doppler it may no longer be necessary to perform preoperative angiocardiography (ANGlO) for patients with a primary diagnosis of uncomplicated unrestrictive ventricular septal defect (VSD). We compared the sensitivity and specificity of both techniques in the detection of additional VSD's and commonly associated lesions using as “gold standard” a combination of surgical findings plus postoperative ECHO's. A total of 130 consecutive patients undergoing VSD repair in infancy between January 1991 and March 1994 were studied. The mean age at repair was 0.48 ± 0.26 year and mean weight at repair was 5.0 ± 1.5 kg. All ECHO's were performed prior to ANGlO. Associated lesions included right ventricular muscle bundles (RVMB), sub-aortic stenosis (sub-AS), and persistent ductus arteriosus (PDA). No case of aortic valve prolapse causing aortic incompetence was identified, and aortic arch abnormalities were generally surgically addressed prior to ANGlO. The sensitivity and specificity of the two techniques in the detection of additional VSD's were: Sensitivity Specificity Echo 63% 99% Angio 63% 95% Out of a total of 8 cases with additional VSD's, 2 were small anterior muscular defects which were clinically insignificant, and only seen by colour-flow Doppler. The results for detection of associated lesions were: Sensitivity Specificity Echo Angio Echo Angio RVMB 73% 73% 93% 96% Sub-AS 63% 38% 96% 97% PDA 80% 80% 98% 99% Our results suggest that ECHO is comparable to ANGlO in the preoperative assessment of uncomplicated VSD in infancy. Therefore, ANGlO should no longer be necessary in the evaluation of these patients.