Purpose: The COVID-19 pandemic is a remarkable health crisis that enforced most people to stay at home and quarantine for a period of time and seems to be having negative impacts on physical activity and mental health worldwide. Autism Spectrum Disorder (ASD), is a neurodevelopmental disorder with a deficit in social interaction characteristics, relationships, and stereotyped behaviors. This study examined Iranian parents’ perceptions of physical activity for their children with ASD during the COVID-19 pandemic. 
Methods: In this study, an explanatory qualitative methodology was used and data were collected via semi-structured phone interviews. The samples included 40 Iranian parents (aged 25-50 years) who had children with ASD according to the Diagnostic and Statistical Manual of Mental Disorders-5 Edition (DSM-5) criteria (aged 7-12 years). 
Results: The results showed that the parents observed their children’s physical activity to decrease greatly than before the pandemic. Parents experienced weight gain, increased anxiety, increased stereotypic behaviors, and decreased orderliness, communicative interactions, and social skills. The parents stated that, when their children were more active before the COVID-19 pandemic, they were more cheerful, more adaptable, and communicated more verbally. Parents believed that physical activities have positive effects on the development of their children’s physical health and behavior. They also reported some barriers to their children’s participation in physical activity. 
Conclusion: Participating in daily physical activity and support from parents were consequential factors in the promotion of their physical and behavioral health and the development of their independent performance and quality of life during the COVID-19 pandemic.