Background: Calcium and vitamin D are important for bone metabolism. The low calcium intake leads to a reduction in the ideal bone mass peak in children with sickle-cell anemia, which determines growth failure. There is little information on BMD in children with SCD and its association with 25(OH)D levels. Objective: To evaluate the relation between Vitamin D level and bone mineral density in children with sickle cell disease. Patients and Methods: This cross-sectional study was conducted over 6 months from February to August 2018. It included 30 patients (14 males and 16 females) with SCD who were following up regularly, at Pediatric Hematology outpatient clinics of Zagazig University Hospitals, their ages ranged from 6-18 years (mean ±SD=12.3+3.84). Results: more than ¾ of the studied group has a deficient level of vitamin D (83.3%). BMD of L1-L4 is normal in only 13.3% of the studied patients and BMD of total body is normal in the fifth of the studied patients (20%). Correlation is non-significant between bone markers and Z-score of BMD, Z-score of BMD L1-L4, and vitamin D level among the studied sickle cell disease cases. Conclusion: Vitamin D deficiency is a major nutritional health problem in patients with sickle cell disease. Emphasizes the need for vitamin D level screening for all SCD patients. Children with SCD have low BMD. There was no statistically significant correlation between vitamin D and (Z-score of BMD L1-L4, Z-score of BMD total body, Osteocalcin, and Beta cross lab) among the studied sickle cell disease cases.