Objectives: Few studies have focused on the participation of children with attention-deficit/hyperactivity disorder (ADHD) in daily routine and leisure activities. This study aimed to compare the participation, support and barriers for children with ADHD at home pre-COVID-19 and during the COVID-19 outbreak. Methods: The study included 55 children with ADHD aged 6-11 years. Participation frequency, involvement, desire for change, supports and barriers at home were assessed using the Participation and Environment Measure for Children and Youth (PEM-CY). Results: During the COVID-19 pandemic compared with the pre-COVID-19 period, the mean frequency of participation of children with ADHD in computer and video games (5.8% vs 5%, respectively), socialising with other people (7% vs 6.2%) and household chores (5.5% vs 4.6%) was shown to be significantly higher (p < 0.05). Mothers of children with ADHD reported higher levels of involvement during the COVID-19 pandemic compared with the pre-COVID-19 period across four areas of home participation, including computer and video games (4.1% vs 3.2%, respectively), arts, crafts, music and hobbies (3.7% vs 3%), household chores (3.6% vs 2.8%) and personal care management (4.2% vs 3.5%) p < 0.05). Mothers of children with ADHD reported that during the pandemic the following two features of the environment made participation easier than pre-COVID-19 (p < 0.05): cognitive demands (36.4% vs 60%, respectively) and social demands (5.5% vs 34.5%). More mothers reported that services (92.7%), supplies (87.3%) and information (85.5%) were available and/or adequate in the COVID-19 period than pre-COVID-19 (p < 0.05). Conclusions: Mothers of children with ADHD reported that their children were participating more frequently in some of the home-related activities during the COVID-19 pandemic compared to pre-COVID-19. Reduced cognitive and social demands, and more readily available resources in the home environment during the COVID-19 period resulted in increased home participation compared to pre-COVID-19. (C) 2021 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.