The mangrove ecosystem of Gilakaladindi, Andhra Pradesh, India was selected for studying the diversity of Streptomycetes spp. and their antimicrobial properties. The soil samples pretreated with CaCO3 were plated on three selective media viz. ISP-2, ISP-4 and HV agar to isolate Streptomycetes spp. Among the 27 strains isolated, 13 possessed antimicrobial activity, of which 7 isolates were active against the test micro-organisms (Gram positive bacteria - Bacillus megaterium (NCIM 2187), Staphylococcus aureus (MTCC 3160); Gram negative bacteria - Escherichia coli (ATCC 9027), Xanthomonas campestris (MTCC 2286) and fungi - Candida albicans (MTCC 183), Penicillium expansum, Fusarium oxysporum). The bioactive strains were further analyzed by polyphasic taxonomy and identified as Streptomycetes harbinensis VJPR-1, S. plicatus VJPR-3, S. coelicolor VJPR-5, S. sodiphilus VJPR- 6, S. nogalater VJPR-7, S. enissocaesilis VJPR-8 and S. xiamensis VJPR-24. The strains have been deposited in NCBI genbank with accession numbers. This is the first report on the diversity studies of Streptomycetes spp. from Gilakaladindi mangrove ecosystem.