Pellagra is a disease largely associated with alcohol abuse, poverty, and malnutrition and is very common in developing countries. However, in the wake of "slimmer is better" fads and the ever-growing population of patients infected with human immunodeficiency virus, it may be on the surge in the United States. This vitamin deficiency disorder, though easy to diagnose and treat, can be easily missed and requires a high index of suspicion. We describe a case involving a patient who presented with the classic triad of "diarrhea, dermatitis, and dementia" and was promptly diagnosed and appropriately treated.