<p>Parasitic infections have been demonstrated to alter the sexual signals of frogs that produce linear vocalizations, leading females to prefer uninfected males over infected ones. Importantly, nonlinear and linear sounds exhibit marked differences in their production mechanisms and functional roles. To gain a deeper understanding of how parasitic infections impact vocal traits and mating preferences in frogs that exhibit nonlinear vocal phenomena (NLP), this study investigated the effects of parasitic infection on the mating signals and sexual selection of two stream frog species whose calls include NLP components: the concave-eared torrent frog (<i>Odorrana tormota</i>) and the large odorous frog (<i>Odorrana graminea</i>). The results revealed that the calling rate decreased with increasing parasitic load, whereas the NLP content increased. Moreover, male frogs engaged in amplexus had higher parasitic loads than those not engaged, presumably owing to their ability to produce calls with higher NLP contents, which are preferred by females. The current study reveals, for the first time, that parasitic infections can increase the NLP content in the courtship calls of male frogs with nonlinear vocalizations, making them more attractive to females; this might be a novel example of parasites influencing host behaviour.</p>