Crustacean eyestalks are known to contain neurosecretory hormones that inhibit molting, growth and gonadal development. Along this framework, this study was conducted to: screen crude eyestalk extracts from the blue crab Portunus pelagicus for possible growth inhibition on two bacterial pathogens Ralstonia solanacearum and Pectobacterium carotovorum subsp. carotovorum. and determine effective concentrations of the crude extract against the pathogens. The screening was done through bioassay using the top agar inoculation technique with 70% ethanol as the extracting solvent and streptomycin as the positive control. Different concentrations of blue crab extract and streptomycin were obtained using serial dilution.