Minimum inhibitory concentrations (MICs) of 12 chemical reagents were determined for four strains of Tenacibaculum maritimum. Bronopol and stabilized chlorine dioxide showed the lowest MIC (1.0 mu g/mL). With 6-h treatment, minimum bactericidal concentrations (MBCs) of bronopol and stabilized chlorine dioxide were 4.0 and <= 8.0 mu g/mL, respectively. Both chemicals were non-toxic to five marine fishes in 6-h exposure at concentrations 5 times higher than the MBCs. The two chemicals are the most suitable candidates for antibacterial agents for treatment of T maritimum infection.