Crude extracts of three actinomycetes species belonging to Saccharopolyspora (TR 046 and TR 039) and Actinosynnema ( TR 024) genera were screened for antibacterial activities against a panel of several bacterial strains. The extracts showed antibacterial activities against both gram-negative and gram-positive test bacteria with inhibition zones ranging from 8 to 28 mm ( TR 046); 8 to 15 mm ( TR 039); and 10 to 13 mm ( TR 024). The minimum inhibitory concentrations ranged from 0.078 to 10 mg/mL ( TR 046); 5 to >10 mg/mL ( TR 039); and 1.25 to 5 mg/mL ( TR 024). Time-kill studies revealed that crude extract of TR 046 showed strong bactericidal activity against Bacillus pumilus (ATCC14884), reducing the bacterial load by 10(4) cfu/mL and 10(2) cfu/mL at 4x MIC and 2x MIC, respectively, after 6 h of exposure. Similarly, against Proteus vulgaris (CSIR 0030), crude extract of TR 046 achieved a 0.9log(10) and 0.13log(10) cfu/mL reduction at 5 mg/mL ( 4x MIC) and 1.25 mg/mL ( 2x MIC) after 12 h of exposure. The extract was however weakly bactericidal against two environmental bacterial strains ( Klebsiella pneumoniae and Staphylococcus epidermidis); and against Pseudomonas aeruginosa (ATCC 19582): the extract showed bacteriostatic activities at all concentrations tested. These freshwater actinomycetes appear to have immense potential as a source of new antibacterial compound(s).