Lavobacterium psyhrophilum affects farmed salmon and trout worldwide and is the etiological agent of bacterial cold water disease. The treatment of this disease is made with antibiotics. The emergence of resistant strains and its ability to form biofilms have increased the resistance to antibiotics. Considering the diverse bioactivity of Antarctic bacteria, we evaluated the inhibitory effect of compounds secreted by Antarctic bacterial strains on the biofilm formation of F. psychrophilum 19749. 26.9% of the Antarctic bacterial isolates inhibited strongly the biofilm, the greatest effect was shown by M19B. Proteins (48-56 kDa) secreted by M19B may be related to the inhibition of the biofilm formation of F. psychrophilum 19749.