OBJECTIVE: To investigate the reliability and validity of 2 commonly used measures of pain related fear in patients with shoulder pain. DESIGN: A preplanned secondary analysis of a prospective single-arm trial involving a repeated-measures design. SETTING: Outpatient physical therapy clinics. PARTICIPANTS: Patients (N=80) with a primary report of shoulder pain. INTERVENTION: All patients completed the outcome measures at baseline and at follow-up. MAIN OUTCOME MEASURES: Patients completed a modified Fear-Avoidance Beliefs Questionnaire (FABQ), the 11-item version of Tampa Scale of Kinesiophobia (TSK-11), and the Shoulder Pain and Disability Index (SPADI) at baseline and at a 48-hour follow-up. Patients were dichotomized as improved or stable at follow-up based on the Global Rating of Change. RESULTS: Factor analysis indicated 3 stable factors for the FABQ and 1 stable factor for the TSK-11. Shoulder specific scoring for the FABQ and TSK-11 were used in subsequent analyses. Test-retest reliability intraclass correlation coefficient (ICC) was substantial for the FABQ and the TSK-11. The FABQ correlated significantly with SPADI pain and disability scores, while the TSK-11 correlated significantly only with SPADI pain scores. The shoulder-specific FABQ-W (work beliefs subscale) was a better than chance predictor of missing days of work during the 48-hour study period. CONCLUSIONS: The modified FABQ and TSK-11 may be appropriate for use in patients with shoulder pain. Shoulder-specific scoring of these measures resulted in substantial test-retest reliability, and the FABQ correlated with the SPADI for pain and disability. The FABQ also showed potential for prediction of short-term work loss in this sample. Pain-related fear may be an important variable in patients with shoulder pain and merits future consideration in longitudinal studies.