Nerve conduction study (NCS) assesses peripheral nerve functions and its parameters are known to vary with anthropometric measurements. This cross sectional normative study was done in Electro-diagnosis Lab II of department of Basic and Clinical Physiology. It was aimed to study the relation of BMI on NCS variables of the peripheral nerves of upper and lower limbs. The study was done in 34 consenting healthy adults of either sex. The anthropometric factors, compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) were recorded using standard technique. The relation of BMI with NCS variables were analyzed using Pearson’s correlation test. After the adjustment of other anthropometric factors, BMI (21.8±2.11 Kg/m2) showed a negative correlation with the CMAP duration of most of the motor nerves: right median (r= -0.388, p<0.005), left median (r= -0.342, p<0.05), left ulnar (r= -0.375, p<0.005), left tibial and right common peroneal (r= -0.347, p<0.05). The CMAP amplitudes of the right median (r= -0.341, p<0.05), left median (r= -0.456, p<0.01) and right common peroneal (r= -0.361, p<0.05); CMAP latencies of bilateral ulnar, left radial and right common peroneal were also negatively correlated. However, a positive correlation was seen with the SNAP amplitude of the right sural (r= 0.441, p<0.01) and a negative correlation with conduction velocity of left median sensory nerve (r= -0.420, p<0.05). The SNAP duration, latency and CMAP F-waves latency did not show any correlation. BMI showed a significant correlation with the NCS parameters of most of the motor and few sensory nerves. Diagnostic conclusions made from the nerve conduction data without corrections for the BMI may be invalid in patients who are at its extreme. This must be also considered while developing standard/reference normative data for different nerves.