This research aimed to investigate the intentions of children on the autism spectrum to participate in physical activity (PA) according to planned behavior theory. In the research, 16 Turkish parents of children diagnosed with Autism Spectrum Disorder (ASD) participated voluntarily. The study group for the research was chosen with the criterion sampling method. Data were collected by preparing a demographic information form and a semi-structured interview form. Face-to-face interviews were held with parents to apply the prepared demographic information form and semi-structured interview form. Data were analyzed with the thematic analysis method. According to the findings, in the behavioral belief dimension, the PA participation intentions of parents were based on the advantages of PA for children on the autism spectrum, and greater contribution to motor development. In the normative belief dimension, children on the autism spectrum were generally encouraged to participate by expert children like special education teachers and doctors. Finally, in the control belief dimension, access and financial opportunities were identified to both facilitate participation in PA and make it more difficult. In conclusion, parents of children on the autism spectrum displayed a positive attitude toward participation in PA. Though they met many obstructing factors, positive feedback from society was effective in their intentions to participate in PA. If the factors making participation in PA more difficult were resolved, it was concluded that participation would significantly increase.