Recently, associations between dental diseases and the general health condition have been reported. The purpose of this study was to evaluate, by serum albumin concentrations, the relationship between the general health condition and root caries. We randomly selected 763 individuals (600 70-year-olds and 163 80-year-olds) living in Niigata City, Japan. The variables body composition, blood measurements, daily nutrient intakes, and root caries were measured. The relationship between root caries and serum albumin concentration was evaluated. The differences in serum albumin concentrations between subjects with untreated root caries (DT = 0 and DT > 3) were 75.56 mg/dL in 70-year-olds and 202.97 mg/dL in 80-year-olds (p < 0.05, ANOVA). The findings of the present study indicated that a relationship between root caries and serum albumin concentration in these elderly subjects is highly possible.