This study set out to evaluate the effectiveness of mindfulness training on parenting stress and parent–child conflicts among parents of children with ADHD. Using a quasi-experimental design with a pre-test–post-test and control group, the research was conducted in Kashan in 2021 with a statistical population of 473 parents. A sample of 30 parents was selected through convenience sampling and randomly assigned to experimental and control groups (15 each). The experimental group received eight mindfulness training sessions, while the control group received no intervention. Parenting stress and parent–child conflict were measured before and after the intervention using the Parenting Stress Scale (Berry & Jones, 1995) and the Parent–Child Conflict Questionnaire (Straus et al., 1998). Analysis of covariance in SPSS-22 revealed that mindfulness training significantly reduced parenting stress (p < 0.01, η² = 0.83) and parent–child conflict (p < 0.01, η² = 0.75), suggesting that mindfulness training can serve as an effective non-pharmacological approach for mitigating psychological difficulties in parents of children with ADHD.