Insulinoma is a rare neuroendocrine tumor that overproduces insulin, resulting in hypoglycemic symptoms. Elevated C-peptide levels in the absence of sulfonylurea use indicate insulinoma. Treatment is usually glucose administration and if the tumor size is large, surgery may be warranted. We present a case of a young man who had a one-year continuing episode of hypoglycemic symptoms that resolve after consuming high-glucose solids and liquids. Although symptoms pointed toward insulinoma, the 72-hour fasting test failed to show insulinoma. This case shows how following the algorithm accurately will prevent an inaccurate diagnosis.