Purpose: To evaluate the signal characteristics of MRI diffusion weighted sequences of musculoskeletal tumors in pediatrics and their corresponding ADC measurements and their ability to differentiate between benign and malignant lesions and their response to therapy.Material and Methods: Between August 2012 and March 2013 thirty two children diagnosed with 20 bone tumours (4 benign and 16 malignant) and 12 soft tissue tumors (6 were benign and 6 malignant) were assessed by conventional and diffusion MR images. Diffusion was carried out by single shot SE-EPI sequence using b values 0, 50, 400 and 800. ADC & EADC were automatically generated on the operating console.Results: The mean ADC of benign tumors was 1.74× 10−3 mm2/s +0.62 while that of malignant tumors was 0.97× 10−3 mm2/s +0.6, P value=0.014. However overlap still exists. ROC analysis produced cut off values 1.1 with a 89% specificity and 80% sensitivity and a cut off value 1.4 with a 78% specificity and 90% sensitivity. They were not ideal and cannot be used as a reliable independent diagnostic test. The mean ADC of tumors that had received treatment was 1.86× 10−3 mm2/s +0.43 which proved to be significantly different from that of de novo malignant tumors, P value= 0.001.Conclusion: DWI and ADC can assist in evaluation of musculoskeletal tumors in conjunction with conventional sequences, but do not have high accuracy. They may be used as markers to assess tumor response. Further dedicated study of a bigger sample is recommended to confirm our results, especially concerning follow up of tumors and the use of perfusion insensitive ADC.