Now a days in Ethiopia the garment industry is playing an incredible role for the economic development of the country. The industry is contributing in foreign exchange earnings, creating a job opportunity for many citizens especially empowering women and in poverty alleviation. Though there is a wide access to the market like through AGOA, COMMESA and others, many garment industries are facing challenges in meeting customer demand in terms of cost, quality and delivery aspects. Lean manufacturing is a systematic discipline or method for the elimination of wastes with in the manufacturing system. In Lean Manufacturing there are many tools of making the process more efficient. Two of those tools are Value Stream Mapping (VSM) which helps to visualize the flow of materials and information flow and Overall Equipment Effectiveness (OEE) which measures the utilization of equipment or line which are available in the manufacturing unit The main aim of this study is to improve the productivity of a garment factory using both VSM and OEE tools. Often VSM focuses on wastes reduction in terms of time and rational material flow but does not address equipment utilization and quality status which is rather solved by OEE and vice versa. The question of the research has been answered with the help of lean tool value stream mapping and OEE helped the case company to lower the non-value adding activity time 21% and increase OEE by 8 % which transform it one level forward and also increase productivity per operator by 12 %. This shows that the lean manufacturing tools known as value stream mapping and OEE are effective and efficient for minimizing the non-value added process and improve OEE result in the Ethiopian garment manufacturing unit. Key Words: - Productivity, Overall equipment effectiveness (OEE), Value stream Mapping (VSM).