Background & aims: Blood pressure is an important sign of cardiovascular, renal and cerebral system function and is the base of making important medical decision. However it is nurses' routine duty, accurate measurement is received little attention. Therefore this study was done to evaluate the quality of blood pressure measuring by nurses.

Methods: This is a cross-sectional descriptive study on 400 nurses of Imam Khomeini hospital complex in 2010 which is carried out through convenience sampling. Personal data Questionnaire and blood pressure measuring criteria's checklist were used for data gathering. Validity and reliability were confirmed through content method and Pearson coefficient(r=0.93), respectively. The quality of measured blood pressure scoring by researchers was categorized to 3 groups. Data were analyzed by SPSS 16. 

Results: There was  difference (p=0.01) between Systolic blood pressure measured by nurses and researcher with aneroid sphygmomanometer while there was no significant difference in diastolic blood pressure (p=0.2). Most of the nurses (60.5%) earned mean score and others (39.5%) earned high score.

Conclusion: According to the findings, the highest percent of blood pressure measurement quality which is an important item to make decision about medical issues was in moderate level.  Thus nurses required to be more accurate and pay more attention to measure blood pressure correctly. Also education authorities should hold retraining courses for nurses.