Background Given the importance and pivotal role of nurses in pain management and control, this study was conducted to determine the nurses’ knowledge and attitudes toward in emergency departments. Methods This study was designed and conducted as a descriptive-analytical cross-sectional study. Nurses’ attitude and knowledge towards pain management and control and relationship between their demographic characteristics have been assessed. Nurse Attitude Survey (NAS) and Pain management and control principles assessment Test (PMPAT) questionnaires were used. Results Totally 400 volunteers, including 148 (37.2%) male and 250 (62.8%) female nurses recruited from 23 hospitals in East Azerbaijan, Iran, with a mean age of 30.88 years (± 6.04 SD) and age range between 22 and 53 years old. The crude mean score of participants’ knowledge of pain management and control was 12.51 (± 2.77 SD), and standardized mean score was 40.34 (± 8.92 SD), which was low at 84.8% and moderate in 15.3% of the participants. Older nurses and nurses who previously participated in pain retraining courses had significantly less knowledge about pain management and control (r= -0.104, P = 0.038), and (r= -0.148, P = 0.003) respectively. The crude mean score of participants’ attitudes toward pain control and management was 15.22 (± 2.56 SD), and standardized mean score was 60.87 (± 10.26 SD). Nurses’ attitudes have become more negative with the increase of their work experience (r = -0.168, P = 0.001), and previously participation in pain retraining courses (r =-0.207, P < 0.001). Older nurses and highly educated nurses had significantly more negative attitudes towards pain control and management (r = -0.153, P = 0.002), and (r= -0.126, P = 0.005), respectively. Conclusions The current study revealed that pain management and control knowledge in most emergency nurses was low, and most of them had a moderate attitude. We need more scientific and comprehensive pain management and control training courses to improve knowledge and attitude among health workers and nurses.