Background and Objectives: Electric and magnetic fields in the workplace are one of the detrimental factors of power plants, transmission lines, electrical wires, and electrical equipments, therefore, exposure to these fields might be harmful for human health. This study aimed to provide information about intensity of the electromagnetic fields at the high voltage electricity posts and its comparison with the threshold limit value (TLV). 
Materials and Methods: The study was conducted at one of the high voltage electricity post in Zanjan City having 63, 230, and 400 KV power transmission lines. After identifying  stations and measuring the intensity of these fields, GIS maps were prepared and the values were compared with permissible values.
Results: The measured magnetic flux density at different parts of the high voltage post showed that the lowest and  highest intensity were 1.69 and 153.7 mG respectively which were lower than the ACGIH TLVs.The lowest and  highest intensity of the electric field  were 0.008 and 38.07 KV/m respectively. The highest value belonged to the 400 KV line, which exceeds the recommended ACGIH TLV (25 KV/m).
Conclusion: According to the results, the magnetic field intensity was below the TLVs, but the intensity of electric field measured in the 400 KV line was greater  than its TLVs. Thus, the strategies and recommendations for reducing exposure should be taken.