ObjectivesTo investigate the intra-rater reliability and validity of belt-stabilized and tension dynamometry to assess hip muscle strength and power. DesignRepeated measures. SettingBiomechanics laboratory. ParticipantsSeventeen uninjured adults (age=22.0±2.3y; 13 females). Main Outcomes MeasuresPeak torque (strength) and rate of torque development (RTD; power) were measured for hip abduction, internal rotation, external rotation and extension using an isokinetic dynamometer, and belt-stabilized and tension dynamometry. ResultsFor peak torque assessment, belt-stabilized and tension dynamometry showed good (Intraclass Correlation Coefficient [ICC]=0.848-0.899) and good-to-excellent (ICC=0.848-0.942) reliability, respectively. For RTD, belt-stabilized dynamometry showed fair reliability for abduction (ICC=0.524) and good reliability for hip internal rotation, external rotation, and extension (ICC=0.702-0.899). Tension dynamometry showed good reliability for all motions when measuring RTD (ICC=0.737-0.897). Compared to isokinetic dynamometry, belt-stabilized and tension dynamometry showed good-to-excellent correlations for peak torque assessment (r=0.503-0.870), and fair-to-good correlations for RTD (r=0.438-0.674). Bland-Altman analysis showed that measures from belt-stabilized and tension dynamometry had clinically meaningful disagreement with isokinetic dynamometry. ConclusionTension dynamometry is reliable for assessing hip strength and power in all assessed motions. Belt-stabilized dynamometry is reliable for assessing internal rotation, external rotation, and extension. Validity of both methods is questionable, considering the lack of agreement with isokinetic dynamometry.