Most cases of diabetes mellitus result from decreased insulin secretion (type I, insulin-dependent) or altered insulin action (type II, insulin-independent). Another category, namely, "other" diabetes mellitus-associated conditions, is usually mentioned to distinguish this type of diabetes from the other two categories; this category includes drugs, genetic and endocrine syndromes, and pancreatic disorders. The most common pancreatic disease that causes diabetes mellitus is chronic pancreatitis that results from alcohol abuse. The clinical observation of patients at our institution with long histories of heavy alcohol intake and diabetes mellitus prompted us to review the impact of alcohol on carbohydrate metabolism. In many of these patients, it was notable that they were not obese and they had no immediate family members with diabetes mellitus, raising the possibility that alcohol-associated diabetes mellitus may be a distinct subset of non-insulin-dependent diabetes mellitus that is distinct from type II diabetes mellitus.