Introduction: The present research which carried out goal was assessing mothvation factors in nurses who in Semnan University of medical science hospitals.Methods: This was a descriptive- analytical study. The statistical population of this research includes 100 nurses who work in critical care units. Study tools were prepared in the basis of the standard questionnaires of Hers berg theory .The collected data were analyzed by spss 11.0 program and using chi square and fisher test.Results: The results showed that nature of work was the most effective factor (52%) and responsibility was low (34%) in internal factors .In external factors supervising (51%) was the most effective factor and salarity (29%) was the low.Conclusion: Internal factors were more efficient than external factors in nursing motivation. Nurses should be maintained by health service system.
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