The purpose of the Activity Scale for Arthroplasty Patients (ASAP) is to develop and validate a self-report questionnaire that demonstrated discrimination of functional gains, low burden, appropriate concurrent validity, and was not limited by ceiling effects. We identified 128 high-functioning hip arthroplasty patients from our database who completed a 25-item ASAP and Lower Extremity Functional Scale questionnaires and a set of anchor questions. Factor analysis identified 10 items associated with 2 distinct factors: (1) activities and (2) running and running-related environments. These 10 items were retained and were identified as the ASAP. The ASAP may be useful in high-level hip arthroplasty patients where other scales fail to capture activities secondary to ceiling effects. In addition, the scale burden is minimized by inclusion of only 10 items.