A clinical study was performed to determine if placement of an amalgam retroseal resulted in elevated blood mercury levels. Ten subjects had blood drawn 7 days before and immediately before placement of an amalgam retroseal. Postoperative blood draws occurred at 7 and 30 days. Blood samples were analyzed for mercury content by Cold-Vapor Atomic Absorption Spectrophotometry. No statistically significant increase in blood mercury levels was detected at 7 and 30 days after placement of an amalgam retroseal as compared with preoperative levels (p = 0.97). Findings support the hypothesis that placement of an amalgam retroseal does not result in significant elevations of blood mercury levels.