To test the hypothesis that male Korean salamanders, Hynobius leechii, respond to water vibrations via the mechanosensory lateral line system, we conducted a series of experiments. First, we examined behavioral responses of males to 0, 0.5, 1.0, and 1.5 Hz water vibrations generated by a model salamander, and we measured the number of times the males (1) oriented their heads toward the vibrating model; (2) approached within a 15-cm–diameter circle centered on the cloaca of the model; and (3) touched the model, as well as (4) the length of time the male stayed within the circle. To determine whether the mechanosensory lateral line system mediated these responses, we measured the same behavioral responses to 1.0 Hz water vibrations (1) both with and without a transparent vibration blocker placed between the model and test males, and (2) after exposing the test males to 0, 0.1, 0.5, and 1.0 mM concentrations of cobalt chloride for 1 h to disrupt the mechanosensory lateral line system. Test males showed significant responses to water vibrations from the model regardless of the vibration frequencies. Males showed significantly lower responses when a vibration blocker was placed and after cobalt chloride treatments. These results indicate that H. leechii males respond to water vibrations via the mechanosensory lateral line system. In addition, we describe aspects of the body undulation of mating males. This is the first clear result in urodeles that the mechanosensory lateral line system plays a role in male-male mating competition.