The purpose of this study was to compare empathy, sleep quality, and social adjustment in students with attention deficit/hyperactivity disorder and cognitive dysfunction syndrome. The method of the present study was basic research in terms of purpose, descriptive in nature, and causally comparative in type. The statistical population of the study included all primary school boys aged 8 to 11 years with cognitive dysfunction syndrome and attention deficit/hyperactivity disorder in Mashhad in 2025, from which 150 people (50 with cognitive dysfunction syndrome, 50 with attention deficit/hyperactivity disorder and 50 normal children) were selected as the sample group through purposive sampling. The research tools included the The Swanson, Nolan, and Pelham Rating Scale (Swason et al., 1981), the Sluggish Cognitive Tempo Scale (Penny et al., 2009), Griffith Empathy Measure (Dadds et al., 2008), Child Sleep Habits Questionnaire (Owens et al., 2000), and the Children's Social Adjustment Scale (Dokhanchi, 1998). Univariate and multivariate analysis of variance tests were used to statistically analyze the obtained data. The results of the study showed that there was a significant difference in terms of empathy, sleep quality, and social adjustment between students with attention deficit hyperactivity disorder and cognitive dysfunction syndrome (P<0.01). Given the problems of empathy, sleep quality, and social adjustment in students with attention deficit/hyperactivity disorder and cognitive dysfunction syndrome, it is suggested that therapists consider interventions to strengthen these variables in these two groups of children in order to improve their social and academic performance.