Introduction/Aims: The conventional recording of F-waves from the vastus lateralis muscle may not accurately measure the F-wave amplitude as the F-wave latency is short and overlaps with the M-wave. However, the optimal stimulation site of the femoral nerve for recording M- and F-waves separately from the vastus lateralis muscle remains unclear. This study aimed to investigate the optimal stimulation site of the femoral nerve to record M- and F-waves separately from the vastus lateralis muscle. Methods: stimulating electrodes were placed medial and lateral to the vastus lateralis muscle (50%, 60%, 70%, and 80% of the distance along a line extending from the proximal to the distal thigh). Each site of the distal thigh was electrically stimulated at random and F-waves were recorded from the vastus lateralis muscle. Each stimulation site was considered to be success if there was no severe pain or discomfort during electrical stimulation of the femoral nerve and no overlap between the recorded M- and F-waves; otherwise, it was determined as a failure. Results: Thirteen healthy men participated in the study. F-waves were successfully recorded in five participants at the 50% sites, eight participants at the 60% site, and twelve participants at the 70% and 80% sites. In cases of failed F-wave measurement, the participants experienced severe pain or discomfort due to electrical stimulation. Discussion: M- and F-waves could be recorded separately from the VL when the relevant branch of the femoral nerve was stimulated in the distal thigh.