Purpose: To identify clinical predictors of pulmonary functions, respiratory and peripheral muscle strength and functional exercise capacity in burn injury patients, and to compare these parameters with healthy subjects. Methods: The study included 47 burn injury patients aged 20-49 years, and 47 age and gender-matched healthy subjects. The patients were evaluated on the day of discharge from hospital. Pulmonary functions and respiratory muscle strength were assessed with a spirometer (Cosmed Pony FX). Hand grip and pain were evaluated with a Jamar dynamometer and visual analog scale, respectively. The six-minute walk test (6-MWT) was performed to determine the functional exercise capacity of the participants. Results: With the exception of FEV1/FVC, all the parameters of pulmonary functions test, respiratory and peripheral muscle strength and 6-MWT distances were lower in the burn injury patients than in the healthy subjects (p < 0.05). Significant predictors for these parameters were age, gender, height, body mass index, total burn surface area, burn injury type, the presence of trunk burn, hand burn, lower limb burn, inhalation injury, and intubation in the burn group (p < 0.05). Conclusions: Burn injury and the demographic characteristics of the patients are important determinants of clinical parameters. These results are clinically important as they can be of guidance in creating a personalized rehabilitation program.