For applications that require clinician use while interacting with patients, usability testing with standardized patients has the potential to approximate actual patient care in a controlled setting. We used hypothetical scenarios and a standardized patient to collect quantitative and qualitative results in testing an early prototype of a new application, the Acute Respiratory Infection (ARI) Smart Form. The standardized patient fit well into the usability testing sessions. Clinicians had a positive response to the standardized patients and behaved as they normally would during a clinical encounter. Positive findings of the ARI Smart Form included that users thought it had impressive functionality and the potential to save time. Criticism focused on the visual design, which could be streamlined, and navigation, which was difficult in some areas. Based on these results, we are modifying the ARI Smart Form in preparation for use in actual patient care. Standardized patients should be considered for usability testing, especially if an application is to be used during the patient interview.