Background & Aim: The aim of this study was to investigate the relationship between nurses&apos knowledge about pain and satisfaction from pain relieving procedures among postoperative CABG patients in selected Tehran medical university hospitals.

Methods & Materials: In this cross-sectional study, 100 nurses were recruited from the ICU Open heart. Also, 200 patients were selected from whom underwent CABG in 24 hours after surgery and were extubated using a simple random sampling method. Data were gathered using two questionnaires including 17 question about demographic characteristics of patients and their satisfaction, and 36 questions about demographic characteristics and nurses&apos knowledge about pain and pain control after the CABG. Data were analyzed using descriptive and inferential methods using SPSS-11.5.

Results: There was not significant relationship between the nurses&apos pain knowledge and the patients&apos satisfaction. However, there were a significant relationship between the knowledge of the nurses about pain control after the CABG and the patients satisfactions (r=0.209, P=0.037).

Conclusion: According to the findings of the study, there were some significant relationships between the nurses demographic and pain knowledge with the pain control after the CABG. There was also significant relationship between patients&apos satisfaction and some of them demographic characteristics.