A case of subcutaneous injection of elemental mercury (Hg) by an adult white female in Gauteng, South Africa is described. The patient had been injecting Hg directly into her breast tissue. The exact quantity of injected Hg and the time period of exposure was unknown. First line of therapy was the surgical removal of the Hg droplets from the breast tissue followed by chelation therapy with 400mg of D-penicillamine given six-hourly over a period of five days. Whole blood samples of the patient were received at the Analytical Services Laboratory of the National Institute for Occupational Health (NIOH) to monitor blood mercury (Bl-Hg) levels. Initial results showed an exponential decrease in Bl-Hg levels after commencement of treatment. By week 18, Hg levels had decreased to 24 µg/L. Further testing needed to be done, however the patient did not present for any future appointments.