Six toothbrushing methods were evaluated using several kinds of toothbrushes. Two kinds of electric toothbrushes were tested also. Forty-two adults who had normal dentition and clinically healthy peridontal tissue, aged 20 to 34, 36 males and 6 females, volunteered for this study. The plaque score was calculated by the modified Volpe's method on which Suzuki et al. reported before. The scoring of the plaque was restricted to the six teeth (formula: see text) The average percentage of plaque removal from the total (labial and lingual) tooth surface by different toothbrushing methods was as follows: (1) 75.2 +/- 9.9% by the Fones method with a hard brush, (2) 71.7 +/- 11.1% by the Scrub method with a hard brush, (3) 67.4 +/- 12.5% by the modified Stillman's method with a hard brush, (4) 64.7 +/- 13.7% by the National electric toothbrush with a soft brush, (5) 62.9 +/- 13.6% by the Roll method with a hard brush (6) 58.1 +/- 16.3% by the Charters method with a brush of a medium hardness, (7) 55.2 +/- 10.2% by the Bass method with a brush of a medium harness. A similar tendency was obtained independently on the labial, lingual and papillary tooth surface. The hard brush was the most effective for the plaque removal by all kinds of brushing methods.