Abstract Background This study evaluates the feasibility of a nine-month advanced quality-improvement program aimed at enhancing the quality of care provided by primary care physical therapists in the Netherlands. The evaluation is based on routinely collected health outcomes of patients with nonspecific low back pain, assessing three feasibility domains: (1) appropriateness, feasibility, and acceptability for quality-improvement purposes; (2) impact on clinical performance; and (3) impact on learning and behavioral change. Methods A mixed-methods quality-improvement study using a concurrent triangulation design was conducted in primary care physical therapist practice. Feedback reports on the processes and outcomes of care, peer assessment, and self-assessment were used in a Plan-Do-Study-Act cycle based on self-selected goals. The program’s appropriateness, feasibility, and acceptability, as well as the impact on clinical performance, were evaluated using the Intervention Appropriate Measure, Feasibility ...