There are many reasons why online self-management education is attractive to both patients and providers. AsthmaWise, an online self-management program, was developed using a Moodle platform, to enable older adults to learn asthma self-management skills. This study aimed to improve AsthmaWise through conducting: usability testing with a sample of end users; a cognitive walk-through undertaken by an independent health researcher; and assessment of content readability. A Perceived Health Web Site Usability Questionnaire score of 67% was achieved, indicating that there were usability issues that needed to be addressed. The cognitive walk-through and readability assessment identified unique issues that were not identified through usability testing with end users. The testing process allowed issues to be identified and rectified before piloting AsthmaWise, creating a more accessible and refined end product. The involvement of the site designer in the testing process was valuable and is highly recommended. This study shows that usability testing involving both end users and experts is an essential part of the design process that is relatively easy and inexpensive to undertake and can be effectively conducted by a nonexpert.