Objective: The aim of this study was to evaluate the effects of iron deficiency anemia (IDA) on peripheral nervous system vianerve excitability tests (threshold tracking).Methods: The study was performed on 32 patients (22 patients (69%) with moderate, and 10 patients (31%) with severe IDA.Parenteral iron treatment was administered based on the calculated iron deficiency. Three nerve excitability tests were performed; Test 1: During the pre-treatment period, Test 2: On the 7th day of the post-treatment period, and Test 3: Three monthsafter the correction of anemia. The strength-duration/time constant (tSD), rheobase and supernormality values of motor andsensory axons of the median nerve were recorded.Results: A statistically significant stepwise increase in the supernormality periods of the sensory axons of the median nervewas detected between the tests conducted in three separate times (p<0.01). This increase significantly correlated with hemoglobin levels but not with iron levels. However, there was no significant difference in tSD and rheobase values between the testson both motor and sensory axons. A significant correlation observed between the increase of sensorial supernormality andhemoglobin levels.Conclusion: The significant increase of supernormality in sensory axons of the peripheral nerves may suggest that chronicischemia occurring in IDA may have some impacts on fast acting K channels. The causes of the decrease in supernormality ofsensory axons can make contribution to the pathogenesis of the patients’ complaints, such as abnormal sensation and dysesthesia in their extremities.