Planning is the most critical phase for the success of any project. If the planning is faulty, the result will be un successful. Hence, the study aims to access the practice and challenges of project planning in Ethio telecom projects. The study used a combination of quantitative and qualitative research approach as both qualitative and quantitative data were collected and analyzed. Descriptive research design was employed in this study. To get the intended data structurally designed questioners were employed which have close ended and open ended questions. Primary and secondary source of data were used. Frequency, percentages and mean were used to analyze the data obtained. The findings of the study revealed that project scope planning, project schedule planning, project cost planning, project resource planning, project procurement planning and project integration planning were practiced well in a limited manner even though more effort is required from the organization to make the practice more effective in creating well organized and attainable project management plan. Whereas, project risk planning, project quality planning, project communication planning, project stakeholder planning and application of planning tools were poorly practiced under the study organization. Major project planning challenges were identified by the study and some of them which is agreed by most of the respondents were: Project implementation was not as per the planed schedule, as a company level culture of following quality standard, policy and procedure were weak, communication gap between key project stakeholders, lack of clarity on communication management plan, poor risk management, lack of adequate top management support, overall standard project management plan was not clearly defined and communicated, poor documentation of lessons learned from previously executed projects, no policy or process was put in place to force the projects to follow the standard project planning practices and lack of adequate project management training. Thus, this study suggested that the organization to pay full attention for every project planning areas and to made more effort to solve problem areas which are identified and analyzed under the study.