Background: Attention deficit hyperactivity disorder and conduct disorder are among relatively prevalent disorders during childhood and adolescence. Considering the negative impact of the parents' drug dependency and bipolar disorder, the present study aimed to determine the prevalence of ADHD and conduct disorder in children of drug-dependent and bipolar parents. Methods: In this case-control study, the case group included two groups of patients with drug dependency and bipolar disorder hospitalized in Shahid Beheshti hospital in Kerman who had 7 to 11-year-old children. The control group included healthy individuals without any drug dependency or other psychiatric disorders. Data were collected using Rutter scale Form A (parents' form) and a demographic questionnaire. Data were analyzed with ANOVA, Chi-square and Tamhane's post-hoc test. Findings: Rutter's abnormal scores were generally 7.11% in children of drug dependent parents, 14% in children of bipolar parents and 1.6% in children of healthy parents demonstrating no significant difference. The frequency of conduct disorder in the bipolar and drug dependent group was higher than the healthy group, but the difference was not significant. The frequency of ADHD was 8.9% in the drug dependency group and 1% in the control group which shows a significant difference. Conclusion: Drug dependency in parents may be a leading factor to mental disorders such as ADHD and conduct disorder in children. Keywords: ADHD, Conduct disorder, Drug dependency .