The goal of this study was to evaluate the efficacy of an equine-assisted therapy programme aimed at improving the psychological well-being of boys in a custodial school of industry. Participants were 39 boys who live in a youth care facility for boys who display problem behaviour. They were from different cultural groups (Black, Coloured, and White) and aged between 14 and 18 years. Horses were utilised in the structured sessions to help the boys learn different coping skills through experiential learning. Data were collected on the boys’ level of coping and subjective well-being in order to assess the efficacy of the programme. The data were analysed using independent groups t-test comparisons. The results showed that the programme significantly improved the boys’ subjective well-being, problem focused coping, and emotion focused coping. However, their levels of dysfunctional coping were unchanged following the intervention. An equine-assisted therapy programme appears to show modest evidence of enhancing psychological well-being of adolescent boys in custodial care.