Physical activity facilitates the acquisition of healthy habits from childhood to adulthood. There are differences in the practice of physical activity between immigrant children and native Spanish children. The aim was to describe physical activity in children, from the perspective of South American immigrant parents. A qualitative case study was conducted. Parents were recruited using purposeful sampling. Data were collected from 12 participants by means of unstructured interviews together with researcher notes. A thematic analysis was applied. The following topics were identified: (a) physical activity and health, (b) socialization, (c) the need for movement, (d) gender, (e) barriers, (f) educational burden, (g) community living, and (h) reason for immigrating. Parents described how physical activity is fundamental and has benefits for health, and for the relationship between children. They perceived that physical activity should not be limited by gender. The time dedicated to other school activities, the norms related to community living, and financial limitations were especially relevant as barriers for the performance of physical activity. These results can be used to revise the curriculum in schools, promote equal opportunities for physical activity and support family participation.