Introduction: Diabetes is the most prevalent non communicable disease in Iran which counts 3 to 5 percent i.e., 2 to 5.3 million people out of the whole population are stricken by the disease. According to the international organizations, concerned with diabetes, every ten seconds, two persons are diagnosed having diabetes and one succumbs. Considering the chronic adverse effects caused by the diabetes, huge economic burdens are imposed on the care and health system. Nurses play a very important role in fulfilling the medical prescriptions and their unawareness about insulin therapy would result in severe injuries to the patients. So, this study aimed at investigating the level of nurses' awareness about insulin therapy.
Methodology: This study was of semi experimental type, in which the population of the study is chosen intentionally. The samples were gathered from Amir-al-momenin and Imam khomini hospitals. The tools included a questionnaire which was divided into two parts. The first part was about the demographic information and the second part constituted 23 questions about insulin therapy then educational pamphlet was given the nurses and two months later, it was resubmitted. The data were gathered and finally it was analyzed by descriptive and deductive statistics.
 Results: The results showed that the most of cases studied (47%) were between 26 to 30 .Besides ,most of them were female (66%).The results also showed that the awareness rate was sufficiently higher after the education (p=0.0001).
 Conclusion: The nurse as one of the main members of the treatment team has the highest contingence and care to the patients, who is directly responsible for injection of insulin. Thus, he/she should recognize the medicine fully and be aware of its maintenance, injection and other essential notes, completely. So, education in the initial phases especially in the diabetes wards is highly needed.