Treatment of Pseudomonas aeruginosa with 1 to 3% d-mannose reduced cell activity indicating the flagella were affected by d-mannose but did not decrease attachment to chicken skin cells. Distance of migration of P. aeruginosa through a hollow tube filled with 1 to 4% d-mannose was reduced when compared with 0% d-mannose. This reduced movement through the tube indicated a possible affect on the flagella. Examination of P. aeruginosa with a light microscope showed that the addition of 1, 2, 3, and 4% d-mannose to a solution containing the organism removed the flagella from 27 to 40% of the cells.