Background: Having an attention deficit hyperactivity disorder (ADHD) child has a disruptive effect on parenting style. As it demands more efforts to be managed and control their behaviors. Insufficient parenting style in childhood can affect the progress of the disorder, worse its signs and symptoms, and increases the risk of development of other behavioral problems, as an oppositional defiant disorder. Aim of the work: We were aiming in this study to assess the relationship between the severity of ADHD and parenting style. Patients and methods: This cross-sectional study was conducted on 100 children who had been attending the psychiatry outpatient clinic from January to June 2019. ADHD was diagnosed with an interview. The ADHD severity and parenting style were assessed by Conner's Parent Rating Scale (CPRS-R-L) and parenting style scale, respectively. Results: The mean age of the enrolled children was 7.91 ± 2.39 years, and 72% were males. The severity of ADHD was 9% mild, 36% moderate, 32% severe, and 23% very severe. There was a statistically significant relation between "negative" or authoritarian parenting style and severity of ADHD (p <0.001). Conclusion: The results of this study demonstrated that ADHD was more common among males with statistically significant relation with parenting style, and a "positive" parenting style may help in decrease the severity of ADHD symptoms.