Fluorophenols are used as agrochemicals and released into environment as pollutants. Cultured marine microalga Amphidinium crassum (Gymnodinium) glucosylated 2-fluorophenol (1), 3-fluorophenol (2), and 4-fluorophenol (3) to the corresponding β-D-glucosides, ie, 2-fluorophenyl β-D-glucoside (4, 60 µg/g cells), 3-fluorophenyl β-D-glucoside (5, 20 µg/g cells), and 4-fluorophenyl β-D-glucoside (6, 40 µg/g cells). On the other hand, 2-, 3-, and 4-fluorophenols were efficiently converted by immobilized A. crassum in sodium alginate gel to give their β-D-glucosides in higher yields (4: 140 µg/g cells; 5: 60 µg/g cells; 6: 100 µg/g cells). In repetitive batch use, the immobilized cells of A. crassum maintained the potential for the glucosylation of the substrate fluorophenol after 5 times of usage.