In 2005, the Department of Health of Executive Yuan showed that 44.4% of elderly in Taiwan fell in their homes, most frequently in the bathroom. One's physical capability is reduced with aging, and thus his or her body mechanics often change. This study tried to develop a set of principles for re-designing/renovating an elderly-use bathroom from an ergonomics perspective, considering anthropometry, human-machine interface, environmental conditions, and workplace design. Thirteen bathrooms were evaluated and provided with recommendations for improvements. These suggestions were compiled to create bathroom re-design and renovation guidelines along with a bathroom assessment checklist, both that may be used more widely to have an elderly-friendly bathroom.