We compared the motor unit action potential (MUAP) measurement parameters recorded with monopolar and concentric needle electrodes from the biceps brachii of 20 healthy adults using automatic quantitative electromyography. Mean MUAP amplitude was significantly greater when recorded with monopolar needle electrode (p<0.001). In contrast, there was no statistically significant difference between electrode types on measurements of mean MUAP duration, rise time of area (p<0.001).