The purpose of this prospective study was to assess whether outcome of speech and language in children 5-10 years after corrective surgery for tetralogy of Fallot (TOF) or ventricular septal defect (VSD) in infancy was influenced by the preoperative condition of hypoxemia or cardiac insufficiency and whether it was associated with perioperative risk factors and neurodevelopmental outcome.A total of 35 unselected children, 19 with TOF and hypoxemia and 16 with VSD and cardiac insufficiency, operated with combined deep hypothermic circulatory arrest and low-flow cardiopulmonary bypass at mean age 0.7 ± 0.3 (mean ± standard deviation) years, underwent, at mean age 7.4 ± 1.6 years, standardized evaluation of speech and language functions. Results were compared between subgroups and related to perioperative factors, sociodemographic and neurodevelopmental status.Age at testing, socioeconomic status and history of speech and language development were not different between the subgroups. In contrast, total scores on oral and speech motor control functions (TFS) as well as on oral and speech apraxia (Mayo Test) were significantly reduced (p<0.02 to <0.05), and scores on anatomical oral structures tended to be lower (p<0.09) in the TOF group as compared to the VSD group. No differences were found for auditory word recognition and phonological awareness as assessed by the Auditory Closure subtest of the Illinois Test of Psycholinguistic Abilities and the test of auditory analysis skills, respectively. In all children, higher age at testing and better socioeconomic status were associated with better results in all domains of assessment (p<0.001 to <0.04). Consistent impairments of all oral and speech motor control functions (TFS and Mayo Test) were present in 29% of all children with a mean age of 6.5 years in contrast to 43% with normal performance and a mean age of 8.3 years. On the receptive speech tasks, only 6% scored below the normal range of their age group. TFS subscores were significantly correlated with age, bypass duration and motor function, but not correlated with socioeconomic status, duration of cardiac arrest, intelligence and academic achievement.Children with preoperative hypoxemia due to cyanotic cardiac defects in infancy are at higher risk for dysfunction in speech and language than those with cardiac insufficiency due to acyanotic heart defects. Age at testing, socioeconomic status, and duration of cardiopulmonary bypass influenced test results. Long-term outcome in speech and language functions can be considered as a sensitive indicator of overall child development after cardiac surgery.Keywords : Speech and language development ; Tetralogy of Fallot ; Ventricular septal defect ; Cardiac surgery Abbreviations : AC, auditory closure subtest of ITPA ; CPB, cardiopulmonary bypass ; DHCA, deep hypothermic cardiocirculatory arrest ; FISH, fluorescence in situ hybridization ; IQ, intelligence quotient ; ITPA, Illinois test of psycholinguistic abilities ; K-ABC, Kaufman assessment battery for childr...