Background: Oral mucositis is a serious complication of chemotherapy. The incidence of chemotherapy induced mucositis ranges from 40%-76% with many studies suggesting that children are more susceptible than adults. Aim: We aimed at evaluating pretreatment dental rehabilitation in protecting from oral mucositis in acute lymphoblastic leukemia children.  Patients and Methods: An open labeled randomized controlled study including 50 newly diagnosed patients with dental caries was conducted. They were classified into a group (A) using standard oral care and group (B) undergoing extended oral care using dental rehabilitation by a pediatric dentist before induction chemotherapy. Results: No differences were observed between both groups regarding mucositis development or severity. Mucositis was more among patients with lower neutrophil count, platelet count and poor compliance to daily oral care (P value <0.001, 0.01 and <0.001) respectively. A positive correlation between mucositis grade and Decayed; Missing and Filled Teeth (DMFT) score and a negative correlation between mucositis grade and neutrophil count were noticed with statistical significance. Conclusion: Although dental rehabilitation before induction chemotherapy did not seem to reduce either the occurrence or grade of oral mucositis, the positive correlation between mucositis severity and DMF score supports the importance of pretreatment dental assessment and rehabilitation in such immunocompromised patients. Neutropenia, thrombocytopenia and poor oral care were found to be risk factors for oral mucositis.