Background: Motivation to exercise in adolescents with asthma may impact exercise adherence and maintenance. Aims: To assess motivational regulations and basic psychological needs (BPNs) to exercise and their association with self-efficacy in adolescents with asthma. It was hypothesized these variables are related. Methods: The study evaluated motivation (intrinsic and extrinsic motivations, amotivation, and self-determination) using the Behavioral Regulation in Exercise Questionnaire-2 - BREQ-2, basic psychological needs (competence, autonomy, and relatedness) using the Basic Psychological Needs in Exercise Scale - BPNES, and self-efficacy through the Adolescent Exercise Self-Efficacy Questionnaire - AASEQ among 148 adolescents with stable disease. Spearman?s correlation coefficient was used. The significance level was 5%. Results: Adolescents were 52% male, 14±2 years and FEV1 95±15% predicted. The self-determination index (SDI-BREQ-2) was 11.8[2.3-16.7], BPNES-Autonomy 3[1.8-4], Competence 3.5[2.3-4.3], Relatedness 3[1.7-3.7], and AASEQ 87[74,8-90,7]. All three BPNs correlated with the AASEQ and ?Management of Symptoms? subscale (0.19 <r< 0.26). BREQ-2 Amotivation (r=-0.16) correlated with the AASEQ ?Medication? subscale, and BREQ-2 Intrinsic Motivation correlated with the AASEQ ?Beliefs About Asthma? (r=0.17). BREQ-2 Introjected Regulation correlated with the AASEQ ?Friends, family and school? subscale (r=-0.17; p<0.05 for all). Conclusions: Adolescents with higher beliefs about their disease and better social interaction perceive more Competence, Autonomy, and Relatedness to exercise, and have higher self-efficacy if they identify fewer external reasons for exercising.