Background Due to improved care, the numbers of patients with tetralogy of Fallot (ToF) are increasing. However, long-term morbidity and need for reinterventions are concerns and also address issues of quality of life (QoL). Methods Patients with ToF and valid EuroQol-5 dimensions questionnaire (EQ-5D) were identified in the national Swedish register on congenital heart disease. EQ5D index was calculated and dichotomised into best possible health-related QoL (EQ-5D index = 1) or differed from 1. Results 288 patients met the criteria and were analysed. Univariate logistic regression showed a positive association between New York Heart Association (NYHA) class I (OR 8.32, 95% CI 3.80 to 18.21), physical activity > 3 h/ week (OR 3.34, 95% CI 1.67 to 6.66) and a better right ventricular function (OR 2.56, 95% CI 1.09 to 6.02). A negative association between symptoms (OR 0.23, 95% CI 0.13 to 0.42), cardiovascular medication (OR 0.31, 95% CI 0.18 to 0.53), age (OR 0.97, 95% CI 0.96 to 0.99) and EQ-5D index was observed. In multivariate logistic regression, NYHA I (OR 7.28, 95% CI 3.29 to 16.12) and physical activity > 3 h/ week (OR 2.27, 95% CI 1.07 to 4.84) remained associated with best possible health-related QoL. Replacing NYHA with symptoms in the model yielded similar results. Conclusion In this registry study, self-reported physical activity, staff-reported NYHA class and absence of symptoms were strongly associated with best possible health-related QoL measured by EQ-5D. Physical activity level is a potential target for intervention to improve QoL in this population but randomised trials are needed to test such a hypothesis.