A guard, fabricated from a water-resistant, lightweight, nonwoven, antimicrobial fabric, is constructed to be worn by a user for protecting a closed, post-operative sternal incision against exposure to water during bathing and showering. The guard avoids the need for manually holding a protective cover over the incision, and thereby frees the arms and hands of the user, or of a caregiver, for washing, lathering and rinsing.