Introduction: About 6% of all hospital admissions are due to adverse drug reactions, the most important determinants in reporting adverse drug reactions is knowledge of health care workers about drug side effects. Since the nurses have an important role in medication orders, this study was conducted with aim to assess the knowledge of neonatal unit nurses about adverse drug reactions at East Azarbaijan province.

Methods: This descriptive and cross-sectional study was conducted in neonatal units of East Azarbaijan province in 2014.  The participants surveyed in this study were 200 nurses who were invited by cluster randomization sampling method. A researcher prepared a questionnaire that investigated the knowledge of participants about adverse drug reactions and was used after approving its validity and reliability. The quantitative analysis of this study used SPSS version 13 by descriptive and inferential statistics. For multivariable explanation of nurses’ knowledge based on independent variables multiple linear regression was used

Results: The mean score of nurses’ knowledge was moderate(12.35±2.36). The highest score was for serum therapy domain and the lowest score was for side effects in oral drugs’s domain. Statistically significant correlation was found between the mean knowledge score with age and work experience (p<0.05). Multivariable  analysis  showed  that  age, work experience  and  history  of  previous  training  were  the  most  important  predictors  of participants’ knowledge.

Conclusion: According to the average level of neonatal nurses’s knowledge about the pharmacology, it is recommended continuing education courses, preparation of facilities for quick access to information about the side effects and drug interactions, as well as providing access to clinical pharmacologists in neonatal units. Also, more experienced nurses should be employed in neonatal units.