Severe acute malnutrition (SAM) affects 12.2 million children globally. Integrating a water, sanitation and hygiene (WASH) kit in outpatient SAM treatment can improve recovery rates by preventing WASH‐related diseases and complications, but its cost at scale remains unknown. This study estimates the cost of integrating a WASH kit, composed of chlorine‐based water treatment, safe water storage with a lid, soap, and a hygiene promotion component into Senegal's national protocol for treating uncomplicated SAM.