This study assessed the plasma and blood concentrations of Cr, Co, and Ni among subjects using removable partial dentures. A comparison was made between subjects with and without RPD treatment history. Control group consisted of 10 healthy individuals without dentures. Concentrations of Cr, Co, and Ni in subjects' plasma and blood were measured with an atomic absorption spectrophotometer. Data were statistically analyzed by ANOVA, and multiple comparison test (alpha=0.05) was used to identify significant differences between groups. RPD use had a significant effect on the concentrations of Cr (P<0.001) and Ni (P<0.05) in blood and plasma. As such, there were statistically significant differences between the control and study groups for the concentrations of Cr and Ni in blood and plasma. However, RPD use exhibited no significant effect on Co concentration in plasma. In conclusion, the use of removable partial dentures with metal frameworks led to an increase in the concentrations of Cr and Ni in both blood and plasma.