Recent advances in optical-fiber technology dictate that attention must be given to establishing accurate and precise measurement techniques. In this paper measurements currently employed to determine the characteristics of optical fiber waveguides are reviewed. Included in the review are techniques for measuring attenuation, delay distortion, refractive-index profile, fiber diameter, and mechanical strength. Since establishment of accurate measurement procedures cannot be accomplished without some knowledge of the physical mechanisms controlling the parameters to be measured, a brief review of the dominant causes of attenuation and modal delay in fibers is also included.