The objectives of this study were to measure the Furcation Entrance Dimensions of first and second permanent molars in Malaysian samples and to compare the Furcation Entrance Dimensions with the blade widths of periodontal Gracey’s curette used for root surface instrumentation. A total of 199 extracted permanent teeth were measured, which comprised of 51 mandibular first molars, 51 mandibular second molars, 45 maxillary first molars and 52 maxillary second molars. Furcation Entrance Dimension was measured using calibrated test gauges. Results showed 51.91% of Furcation Entrance Dimension was <0.70mm. Forty eight percent (48.09%) of Furcation Entrance had Furcation Dimension of more than 0.70mm. It was concluded that 51.91% of all the Furcation Entrance Dimensions of these teeth were less than the blade width of new Gracey curettes. Therefore, new periodontal Gracey’s curette of small dimension may be the best choice of instrumentation and that ultrasonic debridement using a narrow tip may be a more appropriate choice.