Objective.—The main goal was to explore the different toxin properties (proteolytic, hemorrhagic, and neurotoxic) of Leptodeira annulata ashmeadii Duvernoy’s gland secretion (DGS). Methods.—To separate and characterize the different proteins present in L annulata ashmeadii DGS, 20% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was run. To partially purify the proteolytic activity, Mono Q2 column ion-exchange chromatography was used. Hemorrhagic activity was analyzed in chicken embryos and mice (skin and peritoneum). Neurotoxic disorders were analyzed in mice inoculated with L annulata ashmeadii DGS. Results.—The approximate relative mass of 21 protein bands was determined using the MultiAnalyst PC version 1.1 (Bio-Rad) program. L annulata ashmeadii DGS proved to have proteolytic, hemorrhagic, and neurotoxic activities. Conclusions.—Given the properties of the secretions of its Duvernoy’s gland, L annulata ashmeadii should be added to the list of venomous colubrids.