Metabolic acidosis is a frequently encountered acid-base disturbance in hospitalized patients that occasionally develops in the course of treatment with medications used in everyday clinical practice, including propylene glycol-containing drugs (lorazepam, diazepam, etomidate, pentobarbital). Disruption of enterohepatic circulation with activated charcoal is a common practice for several intoxications, including mushroom poisoning. Herein, we present a patient who was hospitalized due to mushroom intoxication and developed severe metabolic acidosis as a treatment side effect rather than from the mushroom poisoning. To the best of our knowledge, this is the first report on propylene glycol-containing activated charcoal-induced metabolic acidosis.