Some bat families perform vocalizations called “songs” to mate, conformed by three element types: chirps, trills, and buzzes. Also, those might be territorial warning calls; but its syntax remains to be understood. Our goal is to get information about mating calls’ patterns and its clarified function for a molossid bat species. We used ultrasound microphones to record vocalizations from a colony of Nyctinomops laticaudatus, during three periods through 2013–2014. We performed spectrogram analysis to characterize vocalizations with chirp number, duration, and acoustic frequency measurements. Results show males perform structured and complex songs. Vocal repertoire features two chirp types, trills, and buzzes as in other species. Chirp A is a short descendant frequency modulated pulse of 8.05 ms (SD = 3.53 ms); chirp B is a downward FM larger than A with an upward final segment of 43.93 ms total length (SD = 14.85 ms). Distinctively Nyctinomops laticaudatus performs songs of a series of three to nine compound chirps, starting with B element of high plasticity. Additionally structure is modified by the syntax, with shorter phrases when the first element is a trill or a buzz.