People working in different professions within an industry or sector are exposed to injuries or diseases due to the improper fitting of workers and work environments. Identification of ergonomic risk factors and analyzing its consequence on the workers’ musculoskeletal is one of the major methodological steps of ergonomic analysis. Among the numerous business sectors, construction industry, a largely expanding and booming industry in the world, contributes to a significant number of occupational accidents and ill health globally. In Ethiopian case, especially in Bahir Dar city, from a total 22 enterprise accidents report, 31.8% accidents are in the construction industry. Due to these accidents and the prevalence of WMSD on the workers, on average 2.71 weekly working days and about ET birr 117429 amounts are lost. These losses occurred due to the failures of assessing ergonomics risk factors periodically and failures of analyzing the consequences of these risk factors as well as lack of using recommended ergonomics risk factor analysis techniques. To address the stated problems, the study devised the main purpose of the study as to assess ergonomics risk factors and analyze the impacts of the identified ergonomics risk factors on the WMSD. For the achievement of this objective, self-report questionnaire survey and observational methods; i.e. REBA, RULA and OWAS methods have been used. By using these methods 47 construction projects and 220 respondents have been taken as a sample size and ergonomics risk factors association with WMSD have been analyzed in basement to this sample size. From the analysis by the self-report questionnaire method it is found that ergonomics risk factors of repetition, awkward back posture, awkward neck posture, awkward shoulder posture, awkward wrist posture and static loading are identified as the prominent ergonomics risk factors of construction industry workers. By the analysis of observational techniques it is found that OWAS overestimate the postural analysis of the case construction industry. Though OWAS overestimate the postural analysis of the case construction industry, REBA and RULA have a capability to analyze the entire body posture by classifying the posture assessments as; upper arms, lower arms, wrist, neck, trunk and leg. REBA also overtake an advantage over the two methods due to the inclusion of dynamic loading and coupling whereas RULA has a primacy advantage to assess the upper limp part over the two methods. As result to be benefited from the primacy advantage of one observational method over another one method; the authors of this study propose the use of the three observational methods simultaneously in Bahir Dar construction industries. In comparison to the self-reporting survey questionnaire method, observation techniques are more powerful for the postural analysis of the construction industry works. Keywords: Rapid entire body assessment, rapid upper limp assessment, work related musculoskeletal disorder, ergonomics risk factors