Purpose Infants exposed to inadequate delivery of nutrients or oxygen are at risk for impaired fetal growth, commonly termed intrauterine growth restriction (IUGR). Multiple studies demonstrate association of low birth weight and IUGR with early and late-onset cardiovascular disease, as well as various measures of impaired aerobic fitness in adolescents and adults. To our knowledge, there are no studies including individuals with history of both IUGR and congenital heart disease (CHD) when evaluating aerobic fitness, nor are there studies evaluating exercise capacity in this population with the Bruce protocol. Thus, the impact of IUGR on exercise capacity in adolescents with congenital heart disease is unknown. Methods We performed a retrospective chart review of a single-institution’s cardiopulmonary exercise stress lab database on patients born after 1/1/1990 with cardiopulmonary exercise testing (CPET) using the Bruce protocol prior to 7/1/2016. We cross-referenced documented birth weight and gestational age to obtain a weight-for-gestational age percentile. Individuals with birth weight < 10th percentile for gestational age were defined as IUGR. Primary cardiac diagnosis was collected from the electronic medical record. IUGR patients were matched with non-IUGR patients by cardiac diagnosis and age at CPET. We excluded patients over 18 years of age at time of CPET, and those without a documented birth weight or gestational age. Results A total of 319 patients were included with 161 (50.4%) IUGR cases and 158 controls. Congenital heart disease was present in 99 (61.5%) IUGR cases and 100 (63.3%) controls (OR 0.9, 0.5-1.4; p=0.74). Age at cardiopulmonary exercise testing was similar between the two groups (IUGR: 12.8 ± 3.6 years, non-IUGR: 12.5 ± 3.5 years; p= 0.51). There was no difference in percent predicted exercise duration (IUGR: 65.5% ± 30.5, non-IUGR: 66.5% ± 28.6; p=0.83). Resting heart rate, chronotropic index, and percent predicted peak oxygen consumption (VO2) were similar between groups. There was no difference in pulmonary function assessment, including fractional exhaled volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio. Regression analyses demonstrated that IUGR was not independently associated with any of the dependent variables studied when body mass index (BMI), gender, CHD, IUGR, and age were also included in the model. Conclusions IUGR is not associated with differences in measurements of exercise capacity using the Bruce protocol in adolescents with CHD. These findings contrast earlier studies showing decreased fitness in individuals with IUGR but without CHD. Further research is needed to study the effects of intrauterine growth restriction on cardiovascular and exercise physiology in patients with congenital heart disease.