The carbamate aldicarb (Temik) is a highly toxic (LD50 = 0.9 mg/kg oral in rats) insecticide often used in agriculture. The authors present a fatal intoxication case with aldicarb, in a 24-year-old male, under police custody in the island of S. Tome and Prince (STP), in Africa. He was found 3 h after his arrest, lying on the floor of his cell, unconscious, frothing at the mouth, and entered into the hospital already dead. Aldicarb analysis was carried out by high-performance liquid chromatography, with a post-column derivatization system (with o-phthaldialdehyde and 2-mercaptoethanol, under alkaline conditions at 80 degrees C) with fluorescence detection at lambda(ex)= 339 nm and lambda(em) = 445 nm. The toxicological analysis revealed toxic concentrations of aldicarb in the post-mortem samples: blood (6.2 microg/ml), stomach (48.9 microg/g), liver (0.80 microg/g), kidney (8.10 microg/g), heart (6.70 microg/g) and urine (17.50 microg/ml). It was also detected to be the same substance in a grey granulate powder supplied by criminal authorities of that country, as a probable substance ingested by the victim. The toxicological analysis results, the autopsy findings and the information given, allowed us to conclude that death occurred due to an aldicarb acute intoxication. Although the case suggested a suicide, particularly based on the known information and on the high aldicarb concentration found in the stomach, it was not possible to indicate precisely its etiology (suicide or homicide).