Nineteen young adult Caucasian males had an average Gingival Score of 0.47. Each was asked to demonstrate his present method of toothbrushing. Thirteen used a scrub method, and six combined the scrub and roll methods. Sulcular fluid measurements were taken from the facial aspect of the mandibular left second bicuspid using filter paper strips stained with ninhydrin. An average value of 0.94 mm was obtained. Intrasulcular brushing was performed in the mandibular left posterior segment, for 30 seconds daily for 40 days. The brushing was done by the investigator on 28 days and by the subjects on 12 days. The average Gingival Index score following intrasulcular brushing was 0.26. Sulcular fluid measurements were again taken from the mandibular left second bicuspid. A decreased amount of sulcular fluid was found in six subjects, while nine exhibited an increase and four showed no change. An average sulcular fluid measurement of 0.87 mm resulted following the experimental brushing period. From these data, it can be concluded that, within the limitations of this study, intrasulcular brushing had no significant effect on the amount of gingival fluid.