Abstract: This review provides an overview of the range of method that has been available to assess Manual Material Handling (MMH) to risk factor related Work-Related Musculoskeletal Disorder (WRMDs). Electronic database was used to search for the material from 1991 until 2015. Method relevant publications on material using electronic database from 1991 until 2015 have been gathered for inclusion in this review meanwhile manual material handling, risk assessment, observational method and musculoskeletal disorder were used during the discovery process. Observational method to assess manual material handling is the purpose for this developed review based on the reliability, validity and risk factor. Two researchers conducted this evaluation process from selected publication. They identified eleven entitled observational assessment tools which were significantly used to assess exposure to MMH related to work-related musculoskeletal disorder. Posture, force, frequency, duration and environment were the risk factors involved in current method in assessing manual material handling. Only one from these eleven methods was confirmed to be reliable and graded as moderate to good. None from this review method conducted validity test. Various observational tools exist but no single tool appears to cover all of the risk factors for manual material handling. In addition, most important factors during developing tool are appropriate validation of exposure assessment method which in the existing observational method, test reliability and validity were not conducted.