Background and purpose: Attention Deficit Hyperactivity Disorder is one of the most common psychiatric disorder of children and adolescents. studies show that depression and other psychiatric disorders are common in families having children with ADHD. Maternal depression affects the prognosis of ADHD. Therefore assessment and management of depression in mothers can play an important role in treatment and prognosis of children with ADHD. Methods: 100 cases of children referred to psychiatric clinic for children were selected. Diagnosis of ADHD were based on DSM-IV-TR and Kaner’ s parental scale. Beck’ s questioner was used for assessment of mothers’ depression. Results: Prevalence of mothers' depression was 40 %. (32% = mild, 7%= moderate, 1%=severe). The most common symptoms of depression were lack of energy (77%), decreased libido (70%), lack of self satisfaction (62%), difficulty in making decision (57%), guilt feeling (54%), feeling penalties (42%), loss of interest in other people (30%). Conclusion: Findings showed that depression in mothers of children with ADHD is more common than general population of women. Correlation between depression and mother’ s academic level was statistically significant. Mothers with higher academic level, have milder depression than others. there is not a significant statistical difference in mothers' depression between two groups of children who received drug for ADHD and those who did not. The number of depressed mothers in the second group were higher than in the first one though.