<p class="abstract"><strong>Background:</strong> The infection by hepatitis B virus (HBV) considers one of the common types of viral disease that can infect all ages of the human. Babies and children as an early age of the human life are usually infected by such type of virus with high incidence rates all over the world. An evaluation of a rapid assay (RA) in comparison with ELISA for diagnosis of HBV infection in early ages patients with a high level of bilirubin was investigated in the present study.</p><p class="abstract"><strong>Methods:</strong> A total of 86 early age patients with high bilirubin levels (35 babies and 51 children) were involved in this study. Sandwich ELISA and RA were applied to detect HBsAg of HBV in the patient's blood samples.  </p><p class="abstract"><strong>Results:</strong> According to the rapid assay, all of our patients were shown a negative result for HBV infection, while the application of sandwich ELISA showed positive results in two of them (child and baby).</p><p><strong>Conclusions:</strong> The RA could be used as a second chose to detect HBV infection after ELISA. The diagnostic device produce by ABNO company which was used as one of the RA was revealed less effective to detect HBV infection.</p>