Aim: The aim of this study was to assess health-related quality of life (HRQOL) following a stationary cycling intervention in children with cerebral palsy (CP). Method: This was a phase I multisite randomized controlled trial with single blinding. HRQOL was evaluated using the Pediatric Quality of Life Inventory SF15 (PedsQL; children) and Pediatric Outcomes Data Collection Instrument (PODCI; parent proxy) before and after a 3 month stationary cycling intervention. Sixty-two children (29 male, 33 female; mean age 11y; range 7-18y) with spastic diplegic CP, classified as levels I to III on the Gross Motor Function Classification System, were enrolled. Paired and independent t-tests were used to evaluate within- and between-group differences respectively. Results: Between-group differences, favoring the cycling group, were found for PedsQL emotional functioning (p = 0.046) and Parental PODCI treatment expectations scores (p = 0.006). Between-group differences were not found for other scales. Within-group improvements were found in the cycling group: PedsQL total score (+5.8; p = 0.006), psychosocial health summary (+6.9; p = 0.008), and school functioning (+8.0; p = 0.038). PODCI satisfaction with symptoms decreased significantly only in the control group (-12.0; p = 0.046). Interpretation: A beneficial influence of exercise on pediatric emotional well-being and parental treatment expectations was found. The evidence was not strong for other aspects of HRQOL. Results support the positive relationship between physical fitness and emotional well-being in the general population. A child's perception is important when examining change in his or her emotional well-being due to intervention.