BACKGROUND: The small ventricular septal defect (VSD) usually presents good clinical evolution, even at long-term follow-up. OBJECTIVE: To verify the clinical evolution of patients with small VSD in order to determine the continuation or not of the expectant conduct, considering the low operative risk, which results in a more liberal indication for surgery. METHODS: From October 1976 to December 2007, 187 cases of small VSD (diameter < 3 mm at the echocardiogram) were evaluated and 155 of them were assessed at long-term follow-up. Time of the clinical manifestation of the murmur and evolution aspects such as the spontaneous closure of the defect (group I) – 64 cases, persistence of the initial size (group II – 74 cases and decrease in the size of the defect (group III) – 17 cases, in addition to clinical complications, were studied. RESULTS: The clinical manifestation of the murmur occurred, in the majority of cases, during the first month of life, corresponding to 48 (75%), 54 (72.9%) and 12 (70.5%) patients, in the three groups, respectively and after the first year of life in 11 (5.8%) patients. Spontaneous closure occurred in the first year of life in 48 cases (75%), mean of 7.6 months and from 1 to 5.5 years in 15 patients (23.4%), with a maximum follow-up of 18 years. The persistence of the defect until 40 years of age was observed. The decrease in the size of the defect occurred on a mean of 15 months, followed for up to 9 years. The probability of VSD closure by the actuarial curve was 34.38% in 1 year and 49.89% in 5 years. There were no clinical complications. CONLCUSION: A favorable evolution of the small VSD at long-term follow-up does not require surgical intervention, with concerns regarding the strict antibiotic prophylaxis.