White rot fungi were able to mineralize the aromatic ring carbon of alachlor to CO₂. After 122 days, 14 and 12% of the alachlor that was initially present in malt extract cultures supplemented with a wood substrate was mineralized at room temperature by Ceriporiopsis subvermispora and Phlebia tremellosa, respectively. Although Phanerochaete chrysosporium mineralized alachlor at 25 °C, it did so more slowly than the other two white rot fungi. The brown rot fungus Fomitopsis pinicola did not mineralize alachlor.Key words: alachlor, mineralization, white rot fungi, pesticide.