We hypothesize that chronic cyanide toxicity may explain the occurrence of calcific pancreatitis in chronic alcoholic individuals in affluent Western nations and malnourished children and young adults in developing tropical regions. In alcoholic persons the source of cyanide is cigarette smoke, and in tropical countries the source could be cassava or other plants. The cyanide hypothesis is consistent with the known epidemiologic and metabolic characteristics of these two contrasting forms of pancreatitis. We believe that continued chronic cyanide poisoning could reinforce any independent effect of alcohol or malnutrition on the pancreas, resulting in an exaggerated and perhaps irreversible form of the disease.