The secretion of virulence factors by parasitic protists into the host environment plays a fundamental role in multifactorial host–parasite interactions. Several effector proteins had been known to be secreted by Trichomonas vaginalis, a human parasite of the urogenital tract. However, a comprehensive profiling of the T. vaginalis secretome remained elusive, as did the mechanisms of protein secretion. We used high-resolution label-free quantitative MS to analyze the T. vaginalis secretome, considering that secretion is a time- and temperature-dependent process, to define the cutoff for secreted proteins. In total, we identified 2 072 extracellular proteins, 89 of which displayed significant quantitative increases over time at 37 °C. To trace classical (Golgi-ER) pathway in T. vaginalis cells, we used beta amylases as model cargo.