BackgroundHealthcare practitioner beliefs influence patients’ beliefs and health outcomes in musculoskeletal (MSK) pain. A validated questionnaire based on modern pain neuroscience assessing Knowledge and Attitudes of Pain (KNAP) was unavailable. ObjectivesThe aim of this study was to develop and test measurement properties of KNAP. DesignPhase 1; Development of KNAP reflecting modern pain neuroscience and expert opinion. Phase 2; a cross-sectional and longitudinal study among Dutch physiotherapy students. MethodIn the cross-sectional study (n = 424), internal consistency, structural validity, hypotheses testing, and Rasch analysis were examined. Longitudinal designs were applied to analyse test-retest reliability (n = 156), responsiveness, and interpretability (n = 76). ResultsA 30-item KNAP was developed in 4 stages. Test-retest reliability: ICC (2,1) 0.80. Internal consistency: Cronbach's α 0.80. Smallest Detectable Difference 90%: 4.99 (4.31; 5.75). Structural validity: exploratory factor analysis showed 2 factors. Hypotheses testing: associations with the Pain Attitudes and Beliefs Scale for Physiotherapists biopsychosocial subscale r = 0.60, with biomedical subscale r = −0.58, with the Neurophysiology of Pain Questionnaire r = 0.52. Responsiveness: 93% improved on KNAP after studying pain education. Minimal Important Change: 4.84 (95%CI: 2.77; 6.91). ConclusionsThe KNAP has adequate measurement properties. This new questionnaire could be useful to evaluate physiotherapy students’ knowledge and attitudes of modern pain neuroscience that could help to create awareness and evaluate physiotherapy education programs, and ultimately provide better pain management.