The multiresistant bacteria still remain one of the most serious clinical problems. This is because these infectious agents are capable to develop different biochemical mechanisms of defense against many synthesized or isolated antibiotics. Nowadays, there is none clinical antibiotic without at least one resistant against it. In attempt to investigate new sources of vegetal, animal or synthetic origins for novel antibiotic prototype, we evaluated ten different materials, including 4 aqueous extracts (Aloe Vera, Kalonchoe brasiliensis, Calendula officinalis and Boehmeria arborescens); 4 Viperidae family snake venoms (Agkistrodon rhodostoma, Bothrops jararaca, B. atrox and Lachesis muta) and 2 synthetic β-lapachone derivatives. Previous sensibility tests showed that none of the vegetal or synthetic materials were able to inhibit the bacterial growth. Therefore, the Minimum Inhibitory Concentration (MIC) determination, by the twofold diluition technique,  was evaluated only for snake venoms against Gram-positive (Enterococcus faecalis, Staphylococcus aureus and Staphylococcus epidermidis) and Gram-negative (Acinetobacter calcoaceticus, Enterobacter cloaceae, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa and Serratia marcercens) drug resistant clinical bacteria isolated from Antonio Pedro University Hospital (HUAP) patients. Experimental results demonstrated that all snake venoms, except for L. muta, showed antibacterial profile only against Gram-positives. A. rhodostoma and B. atrox showed the highest activity against S. epidermidis and E. faecalis, with MIC= 4μg/mL. B. jararaca presented a lower activity against Staphylococcus aureus, with MIC= 13μg/mL. When compared the results with the vancomycin (MIC= 2μg/mL), it is possible suggest that these snake venoms were as active as that, pointing them as a new source of potential antimicrobial agents.