Standard reagents and procedures employed in the Bozicevich Trichinella bentonite flocculation test (BFT) were used, the bentonite particles being coated with the sonicated antigen of Entamoeba histolytica strain DKB. Serum from 84 of 90 persons (93%) with extraintestinal amebiasis were reactive in the BFT, whereas 43 of 50 serum samples (86%) from persons with symptomatic intestinal disease were positive. None of 24 serum samples from asymptomatic carriers was positive, nor was any of 279 specimens obtained from persons with a variety of gastrointestinal, parasitic, bacterial, or virus diseases. The BFT showed good positive-negative agreement (93%) with the indirect hemagglutination test on tests of 121 selected serum samples. The BFT became nonreactive earlier than did indirect hemagglutination in tests on serum from two of five follow-up cases of amebiasis. The BFT is another useful procedure for the serodiagnosis of amebiasis.