Background: Employee participation in decision- making now considered a key element in the successful implementation of new management strategies and plays an important role in determining the degree of empowerment and job commitment of the employee as well as their motivation.  Aim: the Study aimed to identify the effect of using a Developed Guidelines of staff nurses participation in decision-making and empowerment on their organizational Commitment. Research design:  a quesi- experimental research design was used in this study. Setting: This study was carried out at Minia University Hospitals, and Minia general hospital. Sample: 100 staff nurses, working in critical areas, tools: data was collected by using three tools namely I. Decisional involvement scale (DIS) (II), Conditions of Work Effectiveness Questionnaire- (CWEQ), and III.  Organizational commitment questionnaire (OCQ). Results: high level of shared decisions, empowerment and low organizational commitment, highly statistical significant positive association between decision-making, empowerment and organizational commitment. Moreover a Highly statistical significant positive association between empowerment and age, experience and between age and commitment, negative statistical significant in dependent predictors of staff nurses scores of the empowerment and University hospital score. Ministry of health hospital( general hospital) has high level of empowerment and commitment while the decision is made by administration only in contrast  university hospitals has lower level of empowerment and commitment with administration only decision.    Conclusion: high level of shared decisions, lower empowerment and organizational commitment, negative effect using a Developed Guideline of participation in decision-making and empowerment on organizational commitment, Recommendation: Create a unit level DM structures such as shared governance model, unit committees as a strategy for promoting decisional involvement and structural empowerment; create a motivating work environment, keeping open lines of communication.