We report two cases of fatal intoxications with mercury, one intentional and the other allegedly resulting from a drug formulation mistake. Both cases occurred in the year of 2004. The first case refers to a man who ingested a great portion of a mercuric chloride solution. He attended a hospital emergency, submitted to treatment, but died after 49 days. In the second case, a woman applied on the chest skin an ointment containing a great quantity of mercury bromide. After 7 days of treatment in the hospital, she died. In both cases, samples of tissues and organs were collected at autopsy for mercury analysis. Because methylation of mercury in humans after exposure to metallic or inorganic mercury is almost unknown, both total mercury and methylmercury were quantified in the post-mortem samples. The quantifications were carried out by Cold Vapour Generation Atomic Absorption Spectrometry for total mercury and by HPLC-UV for methylmercury. The total mercury contents found in the post-mortem fluid and tissue samples were consentaneous with mercury poisoning. For the first case, the concentrations found, expressed in microg/g wet weight, were in the liver 49.9, lung 3.27 and brain 0.33, and for blood 11.7 microg/mL. For the second case, the concentrations expressed in microg/g wet weight were in the liver 46.6, lung 14.6, brain 0.21, kidney 77.7, stomach 7.12, spleen 6.4 and heart 2.34, and for blood and urine 2.95 and 1.40 microg/mL, respectively. Only in the first case was methylmercury found and quantified in liver (1.70 microg/g wet weight) and in blood (0.15 microg/mL) samples.