This study is conducted to assess the project organization structure practice and challenges in Ethiotelecomrnand also to suggest possible solutions to ease the challenges by identifying the knowledgerngap of the project teams. The researcher has done preliminary interview and observed somernchallenges in each project organization structure related with managing people. As a result thernresearcher was interested to make deep investigation on their human resource management &rnleadership practice on the context of each project organization structure in order to understand theirrnchallenges and also to identify their knowledge gap by taking pure & matrix project organizationrnstructure. Descriptive research design and mixed research approach was applied for this research.rnThe researcher has used hundred percent of the project managers and coordinators, and also usedrnten percent of the project staffs using simple random sampling for the assessment. The results of thernstudy reveal that all the three (Matrix, Functional, and Pure) type of project organization structurernmentioned in the literature are found in Ethio-telecom. The project team has their own selectionrncriteria to select the appropriate project organization structure and they are happy with their choicernin their practice. The study also reveals the challenges associated with each project organizationrnstructure like getting the right staff for the project, maintaining the staff throughout the life cycle ofrnthe project, not rewarding the staff based on their performance, authority and responsibility gap ofrnthe project managers on the project teams. The knowledge gap assessment in each projectrnorganizationâ€™s structure shows that the project teams have poor HRM and leadership practice. As arnresult, the project teams couldnâ€™t able to ease the challenges exist in each project organizationrnstructure as expected. Based on the findings, therefore, recommendations for ethio-telecom projectrnteams are provided so as to manage and lead the projects efficiently in each project organizationrnstructure.