Nursing responsibilities in medication management include prescription, calculation, constitution, checking, administration, patient assessment, documentation and patient medication education. Aim: the study aimed to evaluate the effect educational program regarding drug calculation and administration on nurse's knowledge, skills and commitment. Setting: The study was carried out at general surgical and medical departments in Benha University Hospital. Research design: A Quasi experimental design was used. Sample: convenience sample composed of 103 head nurses and staff nurses working at general surgical and medical units. Tools: Two tools were used for data collection; Drug calculation questionnaire which includes demographic characteristics of study subjects, drug calculation and observational checklist for nurses' commitment. Result: Most of subjects (91.3%) had nursing diploma. Less than three quarters (70.9%) had 1-10 years of experience. Post program; Most of nurses (91.3%) applied formula methods in drug calculation. Regarding nurses' commitment toward drug calculation and administration, there was an improvement in nurses' post program mean scores commitment (78.33+2.21). Positive correlation coefficient was detected among nurses' knowledge, skills, and commitment toward drug calculation and administration. Conclusion: The study concluded that there were statistically significant differences between pre and post program and there were improvements in nurses' knowledge, skills and commitment toward drug calculation and administration. Recommendations: The study recommended that nurses should continue to practice and refresh the different formula types of drug calculations as often as possible with regular self- test of their ability. Further researches should be conducted to detect the relation between drug calculation skills and medication errors.