Necrotizing fasciitis is a rare and potentially fatal infection, with mortality of up to 30%. This case report describes a patient recovering from a laryngectomy for laryngeal squamous cell cancer who developed nosocomial necrotizing fasciitis of the lower extremity due to Serratia marcescens . Only eight cases of necrotizing fasciitis exclusive to the lower extremity due to S marcescens have been previously reported. Patients with S marcescens necrotizing fasciitis of the lower extremity often have multiple comorbidities, are frequently immunosuppressed, and have a strikingly high mortality rate.