Five halotolerant strains of the genus Lysobacter, isolated from two colombian saline springs, were selected by their ability to grow in supplemented media with high concentrations of NaCl, to evaluate the antimicrobial activity of secondary metabolites synthesized by the strains. Supplemented trypticase soy broth cultures were performed with 35 g l-1, 60 g l-1, 90 g l-1 y 100 g l-1 of NaCl. Cultures were centrifuged, the biomass was recovered and subjected to a lysis process and the intracellular fraction of each strain was obtained on which the antimicrobial activity was evaluated. Antimicrobial activity tests were conducted on Escherichia coli, Candida albicans and Fusarium oxysporum. Antimicrobial activity was demonstrated in fractions of USBA 85, USBA 372 and USBA 373 in E. coli and C. albicans. Antimicrobial activity was not evident in fractions of USBA 37 and USBA 353. Fractions of USBA 85, USBA 372 and USBA 373 were desalted on a Diaion HP-20 column. The extracts obtained were analyzed by high performance liquid chromatography (HPLC). The chromatograms showed the presence of compounds in the extracts of the USBA 85 and USBA 372, whereas in extracts of strain USBA 373 compounds were not detected.