The presence of other respiratory pathogens in patients with SARS-CoV-2 infection has been described as a striking feature. However, data on adenovirus co-infection rates and clinical impacts in COVID-19 patients is limited. The purpose of this study is to compare the prevalence of respiratory adenoviruses in children under 15 years of age in Positive and Negative SARS-CoV-2 patients. From September 2020 to January 2021, nasopharyngeal swabs were obtained from 280 patients below 15 years old with influenza-like infection symptoms suspected to be COVID-19 and referred to hospitals in Hamadan province. Nucleic acid was extracted using a High Pure Viral Nucleic acid extraction kit for both viral RNA and DNA. Reverse transcription real-time PCR for detecting SARS-CoV-2 and Real-time PCR for Human Adenoviruses were used. Out of 280 examined samples, 11.7% tested positive for AdV, of which 18 samples originated from the SARS-CoV-2 positive group and 15 samples were from the SARS-CoV-2 negative group. Of 18 co-infected samples, which were categorized in three different ranges of age including, 0-5, 6-10, and 11-15 years old were 11, 4, and 3 patients respectively. Also, 14 patients were hospitalized. Compared with AdV-positive patients, children with Co-infection with SARS CoV-2 had lower levels of white blood cell (WBC) count while erythrocyte sedimentation rate (ESR) and C-reaction protein (CRP) had increased levels. We report a substantial burden of AdV co-infection in pediatric COVID-19 patients. This study revealed most AdV infections lead to hospitalization and change in paraclinical parameters.