This qualitative study investigated the positive and negative outcomes of a home-based strength-training programme for young people with cerebral palsy (CP). Eleven young people with spastic diplegic CP (seven females, four males; mean age 12 years 9 months, SD 2 years 10 months; range 8 to 18 years) and their parents were interviewed. Gross Motor Function Classification System scores ranged from I (walks without limitations) to III (walks with assistive device), with a mode of III. The strength-training programme, which was conducted in the participants' homes three times per week for 6 weeks (total of 18 prescribed sessions), comprised three exercises targeting the major support muscles of the lower limbs. Exercises were bilateral half squats, heel raises, and step-ups. The training load was increased by adding free weights to a backpack so that 8 to 10 repetitions of each exercise could be performed. Using thematic coding, three categories of outcome emerged: body function and structure, activity, and participation, which were influenced by environmental and personal contextual factors. The programme generated overwhelmingly positive outcomes with only minor negative responses about some equipment and the need for parental involvement. Benefits included perceptions that strength, flexibility, posture, walking, and the ability to negotiate steps had improved. In addition, participants reported psychological benefits such as a feeling of increased well-being and improved participation in school and leisure activities. The contextual factors highlighted the fact that sufficient clinician resources must be allocated to solve individual exercise and equipment problems. As well as providing further evidence that strength training can be beneficial, this study provides useful indicators to guide future quantitative studies of outcomes that are meaningful for people with CP.