Objective To correlate nasopharyngoscopic findings with clinical manifestations during the first month of life and study the course of respiratory obstruction during the first year in infants with Robin sequence (RS). Design A longitudinal prospective study of children with RS. Setting Hospital de Reabilitação de Anomalias Craniofaciais, University of São Paulo, Bauru-SP, Brazil, 1998 to 2000. Patients Fifty-six children were studied from the age of 1 month to 12 months. Interventions The type of respiratory obstruction was defined by nasopharyngoscopy. Patients for whom glossoptosis was the only mechanism of respiratory obstruction were classified as having mild, moderate, or severe glossoptosis by nasopharyngoscopy and as mild, moderate, or severe cases with respect to the clinical manifestations. Results Forty-two (75%) patients showed respiratory obstruction caused by glossoptosis; seven (43.7%) of these infants with mild clinical manifestations showed moderate glossoptosis during the first month of life and five (31.3%) presented severe glossoptosis; 10 (45.5%) of the infants with severe clinical manifestations showed moderate and 11 (50.0%) severe glossoptosis. At 12 months of age, glossoptosis was mild or absent in 83.3% of the patients, moderate in 14.3% and severe in 2.4%. Conclusions A poor correlation between the severity of glossoptosis and the severity of clinical manifestations was observed for patients with respiratory obstruction caused by glossoptosis during the first month of life, but the correlation between glossoptosis and respiratory distress according to age was statistically significant. Nasopharyngoscopy is not a good method for predicting the severity of the clinical course of respiratory obstruction caused by glossoptosis.