Sexually transmitted diseases are a major cause of acute disease worldwide, and trichomoniasis is the most common and cur-able disease, generating more than 170 million cases annually worldwide. Trichomonas vaginalis is the causal agent of tri-chomoniasis and has the ability to destroyin vitro cell monolayers of the vaginal mucosa, where the phospholipases A2 (PLA2)have been reported as potential virulence factors. These enzymes have been partially characterized from the subcellular frac-tion S30 of pathogenic T. vaginalisstrains. The main objective of this study was to purify a phospholipase A2 from T. vaginalis,make a partial characterization, obtain a partial amino acid sequence, and determine its enzymatic participation as hemolyticfactor causing lysis of erythrocytes. Trichomonas S30, RF30 and UFF30 sub-fractions from GT-15 strain have the capacity tohydrolyze [2-14C-PA]-PC at pH 6.0. Proteins from the UFF30 sub-fraction were separated by affinity chromatography into twoeluted fractions with detectable PLA A2 activity. The EDTA-eluted fraction was analyzed by HPLC using on-line HPLC–tan-dem mass spectrometry and two protein peaks were observed at 8.2 and 13 kDa. Peptide sequences were identified from theproteins present in the eluted EDTA UFF30 fraction; bioinformatic analysis using Protein Link Global Server charged with T.vaginalis protein database suggests that eluted peptides correspond a putative ubiquitin protein in the 8.2 kDa fraction and aphospholipase preserved in the 13 kDa fraction. The EDTA-eluted fraction hydrolyzed [2-14C-PA]-PC lyses erythrocytes fromSprague–Dawley in a time and dose-dependent manner. The acidic hemolytic activity decreased by 84% with the addition of100 μM of Rosenthal’s inhibitor.