Proper Construction site organization is recognized as an important exercise in order to achieve better performance of construction projects. Success in construction project is indicated by its performance in the achievement of project time, cost and quality objectives. Construction projects found in Ethiopia, as well as in Amhara region specifically in Bahir Dar City run as high extensive time loss and cost overruns. While to some extent the influence of improper handling of material in Construction site organization on labor performance, cost and time is inevitable in construction projects, here it is necessary to improve improper handling management practice to minimize the negative impact on labor performance. In a construction project, most of the time-poor construction site organization management systems and its were on labor performance informed the need for this study. The objective of the study is to assessed the effect of construction site material handling practice, to assess the influence of safety management practice at work site and to identify factors that affect labor performance in public building construction projects. The extent of the Construction site organization and the effect of material handling practices on labor performance. The Construction site organization management system at building construction project include: material handling practice, safety management practice at work site and the factors affecting the labor performance in Construction site. The study was targeted to the selected clients, consultants, and contractors on targeted active projects in Bahir Dar City Amhara region. The study used both qualitative and quantitative methods of data collection. Literature review, physically delivered questionnaires and structured interviews and desk study were used to collect data. The collected data were analyzed using mean scores index (MSI). According to the result the most severe problems, effects, impacts and factors on-site organization were discussed briefly. Therefore, the study concluded that stakeholders should improve their supervision on-site, materials should be adequately handled when delivered as well as in working progressed, care should be given to materials handling process and more awareness should be given to the knowledge of materials management, impact of safety management practice at work site and factors of labor performance in building construction projects most especially on construction sites. Finally having the above-raised clues conclusions and the recommendations had been forwarded.