Purpose of the study: The purpose of this study is to find out the relationship between the rooms need is leadership style and the nurses work achievement. Methodology: This research applied study cross sectional design by talking 43 nurses of RS SidoWarasMojokerto as the respondents. The method is questionnaire for leadership style and observation for work achievement. The result show leadership style causing the nurses work achievement low indicated in 7 person (16.3%), 4 person (9.3%) is good for democratic leadership style that low educated in 6 person (14.0%), and good 26 person (60.5%). This research used statistical analysis Chi-square for now. The relationship between the room head's leadership style and nurses work achievement is 7.819 > x² table with df=1 is 3.841 with significant value (p) is 0.005 less that alpha 0.05 and fisher's exact test 0.009 (p<0.05) that Ho is rejected and H1 is accepted. OR of 7.583 Main Findings: The nurse work achievement in influenced by several factors.one of them is the leadership's style. If the leadership style affects positively to work achiviement, it will improve the service quality. On the ather hard if I affects negatively. It will reduce the service quality. Applications of this study: That between leadership style and the nurses work achievement there is a significant relationship. Novelty/Originality of this study: To apply leadership style characteristic of the subordinates and the condition to give skill training to develop their knowledge and to improve the achievement and to conduct a further research on the leadership style.