The present invention relates to the use of a Compound of formula I,preferably 4-[3,5-bis(2-hydroxyphenyl)-[1,2,4]triazol-1-yl]benzoic acid or a pharmaceutically acceptable salt thereof for the preparation of a medicament for use in the treatment of biofilm formation, e.g. of P. aeruginosa, e.g. in cystic fibrosis patients.