Background:The purpose of this study was to determine the level of vitamin B 12 among personnel working in the operating room of Shahid Beheshti Hospital in Isfahan.Methods: This study was conducted on 51 personnels of Shahid Beheshti Hospital operating room. First, demographic information of the participants was obtained. Then blood samples were acquired for determining the level of vitamin B 12 and subsequently, a neurologist examined the health status of the participants' nervous system.Results: Low levels of vitamin B 12 were reported in 25 participants, and 26 participants had normal levels of vitamin B 12 . The participants were divided into two groups: vitamin B 12 deficiency group and normal vitamin B 12 group. There were no significant differences between the two groups regarding age, work experience, working hours per day, working days per week and neurological examinations (P > 0.05). Anesthesiology technicians were at a higher risk for vitamin B 12 deficiency compared to the surgical technologists, nurses and practical nurses (P < 0.001). In all occupations, the results showing normal examinations were more than impaired examinations, but these differences were not significant (P > 0.05).Conclusion: Vitamin B 12 deficiency is observed in a significant proportion of individuals in the study, and anesthesiology technicians have lower levels of vitamin B 12 than other operating room personnel. There was no significant association between reduced vitamin B 12 levels and neurologic complications in this study.