A 4-month study was conducted at the University of Maryland Pediatric Hematology/Oncology Clinic to determine the incidence of oral complications as well as the value of early dental intervention as part of the support therapy for pediatric oncology patients. This study is important because of the limited number of reports that currently describe oral assessment and management of oral complications in these patients. Initial oral examination and subsequent evaluations were conducted over the 4-month period. Thirty-six pediatric cancer patients with leukemia or solid tumors who were newly diagnosed or receiving maintenance therapy for their malignancy during this period were evaluated. The relationship between the diagnosis of cancer, therapy, type of oral complication, and response to dental intervention was studied. Sixteen patients (44%) experienced a total of 21 oral complications requiring immediate dental intervention during their cancer therapy. Complications included acute and chronic xerostomia, mucositis, oral infection during tooth eruption, and acute pulpitis. Children with a history of routine dental care prior to their cancer therapy experienced fewer overall oral complications. The findings demonstrate that further comprehensive prospective investigations are necessary to enhance our knowledge to manage oral complications in this critically ill group of patients.