From 1987 to 1994, 31 cases of acute paraquat poisoning were managed in the CHRU of Pointe à Pitre (FWI). Eighteen patients died, 13 survived. Biological indexes accurately predicted patient's outcome in all cases out of one. In the last case biological parameters were mislead ing : the corresponding patient survived despite consistent clinical and biological prognosis of death. The unexpected survivor was West Indian, male, agricultural worker of 26 years who alleged drunk about 300 ml of gramoxone (20% v/v paraquat) in a suicide attempt. The patient was HIV infected (Elisa+, Western-Blot+) and presented an AIDS syndrome (CD4 count inferior to 200 cells/mm3) estab lished since 10 months and treated by AZT. We could not identify any other distinguishing features among the unexpected survivor and the rest of the patients. This observation suggests that the immunological status of the patient could explain this protection from paraquat toxicity