In an effort to increase physical activity (PA) in children, some schools are utilizing after-school PA programs. For after-school PA programs to attract children and their parents more effectively, it is important to understand participant perceptions. With input from parents and children, after-school PA programs will be better equipped to attract children to the PA program, resulting in greater participation, enjoyment, and increased PA. Thus, the purpose of this study was to gain insight into parents’ and children’s thoughts and decisions relating to joining an after-school PA program. A cross-sectional qualitative design was employed. Children were interviewed and parents were surveyed prior to youth involvement in Step Up for Health, an after-school PA program geared toward youth of a Midwest elementary school. Responses to the surveys and interviews were coded into categories. Thirty of 39 youth students reported participating to increase their physical fitness levels. Thirty-seven of 39 youth participants identified their physical education teacher as being influential in their decision to participate. Thirty-nine of 39 parents/legal guardians stated the main benefit of the program was that it provided a PA outlet for their child. Every adult participant identified their own child as an influential figure in the decision-making process to allow their child to participate. Perceptions held by parents and children provided insight into the recruitment process for PA programs. The theory of reasoned action can serve as a guide to understand why participants and their parents support such a program.