Fomepizole is used to treat and prevent toxicity from ethylene glycol poisoning. Treatment with fomepizole without hemodialysis in massive ethylene glycol ingestion has been rarely reported in the literature; however, published literature and practice guidelines recommend considering dialysis for ethylene glycol levels >50 mg/dL. We report a case of massive ethylene glycol ingestion resulting in the highest serum ethylene glycol concentration in a patient without ethanol co-ingestion who was treated with fomepizole and was not hemodialyzed. A 48-year-old male presented to the emergency department after reportedly ingesting >1 liter of antifreeze in an attempt at self-harm. He denied concomitant ethanol consumption. His initial presenting serum ethylene glycol level was 700 mg/dL, with normal renal function, and a metabolic acidosis with a high anion gap. One hour after presentation, he was started on intravenous fomepizole. Treatment with fomepizole continued until the patient's plasma ethylene glycol concentration was 16 mg/dL. His metabolic acidosis quickly resolved, he had no adverse reactions to the treatment, and his renal function remained normal. Ultimately, he was discharged to a psychiatric unit without sequelae. Published literature and practice guidelines suggests considering hemodialysis initiation in patients with an ethylene glycol level > 50 mg/dL. This recommendation is anecdotally, rather than evidence, based. With the potential risks inherent in hemodialysis, our case provides evidence that treatment with fomepizole without hemodialysis appears to be a viable alternative option in patients with even extremely high plasma ethylene glycol concentrations as long as their renal function is intact.