Here we report the first characterization of the endemic Mount Bulgar Viper (Montivipera bulgardaghica) and Radde's mountain viper (Montivipera raddei) venom by a combined approach using intact mass profiling and bottom-up proteomics. The cytotoxicity screening of crude venom as well as isolated serine proteases revealed a high activity against A549 human lung carcinoma cells. By means of intact mass profiling of native and reduced venom we observed basic and acidic phospholipases type A(2). Moreover, the analysis revealed snake venom metalloproteases, cysteine-rich secretory proteins, disintegrins, snake venom serine proteases, C-type lectins, a vascular endothelial growth factor and an L-amino acid oxidase. (C) 2017 Elsevier Ltd. All rights reserved.