Surgical repair of tetralogy of Fallot (TOF) in countries with sound medical care systems is seldom delayed until adolescence. This study investigated the clinical profile and the surgical outcomes in such a population from Taiwan. Between 1970 and 2009, 179 TOF patients (56% male) received total repair at 19.2 ± 8.3 (10-49) years of age. We reviewed the medical records and interviewed the patients concerning their current status. The survival was ascertained in all by a link to our national health database. Major morbidities before cardiac repair included atrial arrhythmia (1.1%), ventricular arrhythmia (3.9%), infective endocarditis (6.7%), brain abscess (4.6%) and pulmonary tuberculosis (3.3%). Ventricular arrhythmia and pulmonary tuberculosis occurred mainly after 20 years of age. Thirty patients (16.8%) received a palliative shunt. The preoperative QRS duration increment was 0.6 ms/year. Early mortality occurred in 4 (2.2%) and was related to previous shunt surgery (OR = 16.5, p < 0.05) and coronary artery crossing RVOT (OR 17.6, p < 0.05). After repair, the functional class improved in all patients. The median age at latest follow-up was 31.8 (32.8 ± 12.3) years. The survival was 92.7 and 89.3% at 20 and 30 years after operation, respectively. Late cardiovascular death could be predicted by the length of postoperative intensive care unit stay (OR = 1.3, p < 0.001). The freedom from ventricular arrhythmia 30 years after repair was 84.1% and was associated with a final QRS longer than 160 ms. Unrepaired TOF patients were at high risk of infective endocarditis, brain abscess, pulmonary tuberculosis and arrhythmias during their adolescence and adulthood. Cardiac repair in this age group was still safe and effective.