Cholestasis can be defined as the accumulation of substances normally excreted in bile e.g. (bilirubin, bile acids, and cholesterol). The process occurs as a result of impaired bile formation by the hepatocytes or from obstruction to the flow of bile through the intra-hepatic and extra-hepatic biliary tree. The aim was to make laboratory assessment of bone mineral status and detection of different biliary diseases severity, duration and applied management on these laboratory values. The present study included forty patients, twenty four were males (60%) and sixteen females (40%) who had cholestatic liver diseases for more than 3 months and were followed up in the hepatology clinic, Cairo University and twenty healthy age and sex matched controls. The mean for age was 2.1 ±1.22 years among cholestatic patients and the duration of illness was 1.94 ±0.97 years at diagnosis. The most common cause was neonatal hepatitis, ten cases (25%). The most common finding was hepatomegally (90%). Cases had a significantly lower level of vitamin D and calcitonin hormone compared to controls, P= (0.005, 0.006) respectively. Vitamin D deficiency was more in fourteen patients who were not compliant on treatment. The mean level of calcium was 8.2 mg/dl and phosphorus 3.4 mg/dl. Cases had a significantly lower level of vitamin D and calcitonin compared to controls, P= (0.005, 0.006) respectively. There was no significant difference observed between cases and controls regarding PTH level. There was a negative correlation between PTH and calcium level (r=0.3, P=0.03).