Background: Childhood cancer in Egypt is a growing concern for the society. The role of vitamin D as promising anticancer agent is evident. A limited number of studies have examined vitamin D status among pediatric oncology patients. Aim of the Work: was to detect some risk factors of childhood cancer, to assess level of vitamin D and identify factors influencing its level in newly diagnosed cancer children and controls. Subjects and Methods: A case control study was designed including 160 children, aged 1 to 15 years. 80 children were randomly chosen from newly attendants of the National Cancer Institute in Cairo, while controls were recruited from healthy children accompanying parents in a polyclinic in Cairo. The questionnaire included, beside characteristics of parents, risk factors of childhood cancer. A subsample (40 cases, 40 controls) was investigated for serum vitamin D. SPSS 17 was used for statistical analysis. Results: 63.8% of the diagnosed cancer children were males compared to 55% of controls. Hematological tumor was the most predominant type. Significantly more cases than controls were of higher birth order , had older fathers, less educated mothers, positive family history of cancer, no folic acid supplementation of mothers during pregnancy, and low vitamin D level (p=0.000). In addition, they mentioned less frequent sun exposure days, incorrect timing of exposure, and lack of sport participation. Conclusion: It is concluded that deficiency of vitamin D, family history of cancer and lack of maternal folic acid were detected as significant risk factors of childhood cancer.