The UV-VIS behavior of (E)-1-((2-hydroxy-5-methylphenyl)diazenyl)naphthalene-2,7-diol and the acrylate derivatives and their chromium complexes were determined in different solvents, pH and temperature. The dyes were found to exist in azo and hydrazone tautomeric equilibrium in solution. And also, the o,o’- dihydroxyazo dyes and chromium complexes were tested for antimicrobial activity against Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeroginosa, Escherichia coli and Candida albicans. Dye I generally affected all microorganisms, while compounds II, III and IV were more effective against P. aeroginosa and E. coli. Because dye I has an antimicrobial effect on both bacteria and fungus it finds good use in various applications such as textile fiber dyeing, and biomedical studies. Significantly, this dye could also lead to the development of new antifungal drugs.