In our department, 35 patients with atrioventricular canal underwent elective surgery between June 1983 and May 1989. The diagnosis was based on clinical and echocardiographic assessment without cardiac catheterization. Nineteen patients (age 2-12 years; mean 6.6 years) had a partial atrioventricular canal and 16 (age 5-8 months; mean 7 months) presented a complete atrioventricular canal. The echocardiographic diagnosis was confirmed at surgery in all but one patient (2.8%). The latter was diagnosed as having a complete canal but at surgery a transitional canal with a restrictive ventricular septal defect was found. We based our patient selection on the natural history which excluded cases with early heart failure and pulmonary hypertension. We also relied on an accurate morphological study using two-dimensional echocardiography which excluded cases with associated cardiac malformations. Our recent experience (1986-1989) showed that 50% of the patients with complete canal and 60% of patients with partial canal underwent surgery without cardiac catheterization.