In recent decades there has been an increase in the occurrence of dental root surface caries, especially among adults and senior citizens. This study aimed to identify root surface caries prevalence in adults and seniors from southeast São Paulo State, Brazil. An epidemiological survey was carried out among 1,475 dentate adults, ages 35 to 44 and 65 to 74, respectively, according to WHO criteria. Root surface caries prevalence was 15.6% and 31.8%, for the 35-44 and 65-74-year groups, respectively. The average rate for decayed and/or filled roots was 0.36 for the middle-aged adult group and higher in males (p < 0.01), as compared to 0.82 for seniors, with no difference by gender. The average rate of decayed roots was 0.18 and 0.53 for middle-aged adults and seniors, respectively; in both groups the levels were higher among men (p < 0.01). Further studies on oral health, mainly on root surface conditions, are essential in both middle-aged adults and senior citizens.21311-6