Reliability of goniometric measurements has been examined only under standardized conditions and usually within healthy subjects. The purpose of this study was to assess goniometric reliability in a clinical setting. The reliability of goniometric measurements of passive elbow and knee positions was assessed using patients as subjects. The effect of using the means of repeated measurements and the interdevice reliability of three common goniometers were also examined. Results showed that intratester reliability for flexion and extension of the knee and the elbow joints was high (r = .91 to .99). Intertester reliability was also high (r = .88 to .97) for these measurements except for measurements of knee extension (r = .63 to .70). Although previous investigators have suggested that using the means of multiple measurements improves reliability, our data indicate that this procedure never improves the correlation coefficient more than .12. The reliability was similar for all three devices. The results of this study indicate that for the knee and elbow joints, goniometric measurements performed in a clinical setting can be highly reliable. The method described in this study provides a simple protocol that can be used clinically to investigate goniometric reliability.