Background and objective: Entrance skin dose is the value of the radiation absorbed dose by the skin where the X-ray beam enters the patients. Assessment of entrance skin doses, specifically for pediatric radiology, is very crucial as the children are dividing cells rapidly and are more sensitive to radiation than adults. Their cells can be easily damaged by excessive radiation dose. This study is considered as an attempt to evaluate the effects of diagnostic X-ray on pediatric patients throughout measuring the entrance skin doses and hematological parameters for pediatric patients. Ways of protecting themselves from X-ray hazards is also included. Methods: A case-control study was used to collecting the data for 70 pediatric patients from October 2015 to August 2016 at Radiology Departments of five governmental hospitals throughout Hawler city the capital of Kurdistan Region-Iraq. Pediatric patients aged between (1 day -6 years) they were divided into case and control group by which 40 of them had got diagnostic X-ray examination as (case group) and 30 of them had not had past history of taking X-rays as (control group). Entrance skin dose was measured indirectly via parameters such as a focus on skin distance, tube voltage (KV) and tube current (mAs) in an arithmetical equation. Results: High level of entrance skin doses were received by pediatric patients in this study. Also, it was found that diagnostic X-ray has effects on pediatrics white blood cells and platelets with the significant difference between case and control group and p-values (< 0.001 and 0.006) respectively. Conclusion: Entrance skin doses levels received by pediatric patients in this study was higher than other studies level and then pediatric patients will be at risk if they are exposed to unnecessary exposure to ionizing radiation. It is important to focus on improving pediatric radiography for reducing the hazards of X-ray radiation on pediatric patients.