The bioremediation rate of fluazifop-p-butyl (C19H20F3NO4) was monitored. Bacteria were isolated in agricultural soil samples. Fifteen sterilised glass jars were inoculated with 2, 5, 10, 20 cm(3) of a homogenised bacterial mixture (10(9) CFU/cm(3)), then sterile agricultural soil and 60 mu g of fluazifop-p-butyl (in liquid form) were added to each jar. Each week, filtrated water drained from bottles was analysed for fluazifop-p-butyl concentration, chemical oxygen demand (COD), biochemical oxygen demand (BOD5) and total organic carbon (TOC). Additionally, pH and dissolved oxygen concentration were monitored. The highest biodegradation rate was observed in the soil sample containing 20 cm(3) of the culture media. In this media, fluazifop-p-butyl, COD, BOD5 and TOC removals were measured as 91, 83, 96 and 86%, respectively, at the end of the 2 months. The DO level was measured between 3 and 6 mg O-2/dm(3) in the first month for all cultures. An increase of pH was recorded during the first month and after this time a pH decrease was noted.