PURPOSE--To study the surgical and clinical evolution of 32 cases with absent pulmonary valve to propose the ideal period of time for surgical correction. METHODS--Clinical and laboratorial analysis were performed in 32 infants, under 12 months of age, between 1980 an 1993, in an evolutive character. From the clinical viewpoint, hypoxic and/or congestive features were considered in previous and late periods related to surgical repair. Laboratorial studies as ECG (cavities overload), chest X-ray (cardiac size and pulmonary vascular markings) and echocardiogram (associated defects, pressure gradients and anatomical aspects of pulmonary arteries) were also analyzed. Cardiac catheterization was performed in 15 patients. RESULTS--Early cyanosis in 84 of cases and "to and for "murmur in 90 of them facilitate clinical diagnosis in whom tetralogy of Fallot was associated in 30 patients. Refractory respiratory and cardiac insufficiency were responsible for operative indication in 12 patients, half of them, operated on under 12 months of age, died. Survival patients were repaired between two to 11 years old. Four deaths occurred early in life, before any surgical consideration and the 16 remaining patients will electively be considered for an opportune repair. CONCLUSION--Conservative clinical treatment is indicated, waiting for a more rigid bronchial wall can support the pressure of the dilated pulmonary arteries. This way, surgical repair is postponed for at least two years of age.