Objective: To examine the current evidence regarding the reliability and validity of hand-held dynamometry for assessment of muscle strength in the clinical setting. Data Sources: A search was conducted of the following databases: Cochrane, MEDLINE, PubMed, PEDro, OTseeker, Index to Chiropractic Literature (ICL), and MANTIS, from inception until January 29, 2010. Study Selection: The MeSH subject heading "muscle strength dynamometer" was searched, in isolation and in combination with the text word phrases "hand-held dynamometer" and "isokinetic." Four hundred fifty-four different studies met this search and were reviewed for possible inclusion. Data Extraction: Two independent reviewers assessed the quality of the included manuscripts. The PEDro data collection system was used in conjunction with the Cochrane Diagnostic Test Accuracy Description. A third reviewer was used when there was disagreement between the primary reviewers. Data Synthesis: Seventeen manuscripts met the inclusion criteria for this review, with a total of 19 studies (2 of the manuscripts involved 2 separate studies) that compared hand-held dynamometry with an identified reference standard (isokinetic muscle strength testing). The results demonstrated minimal differences between hand-held dynamometry and isokinetic testing. Conclusions: Considering hand-held dynamometry's ease of use, portability, cost, and compact size, compared with isokinetic devices this instrument can be regarded as a reliable and valid instrument for muscle strength assessment in a clinical setting.