Planning is the process of thinking about activities required to achieve a desired goal.rnConstruction planning is the process of determining appropriate strategy for thernachievement of predefined project objectives. In construction projects, the objective ofrnconstruction planning is the completion of prescribed amount of work within fixedrntime, at a previously estimated cost and to a specific standard of quality. In thernEthiopian construction industry however, construction planning effort usually fails tornachieve its objectives. Even large construction companies who practice planning tornsome level, frequently have difficulty in achieving their predetermined goals.rnThere is, therefore, a need to examine construction practices and develop strategies forrnimproving construction planning effectiveness. With this in mind this research tries tornidentify the main factors that influence effective construction planning in Ethiopianrnconstruction industry. Thus, 19 factors were identified from comprehensive literaturernreview and the industry overview. Using questionnaire survey their degree of impactrnon planning effectiveness were assessed by planning practitioners working in largernconstruction companies. And their corresponding severity indices were used forrnranking whereby the agreement among the practitioners in ranking the factors wasrnconformed using coefficient of variance test.rnThe findings indicate that lack of adequate investment of time and money on planningrnphase and inadequate qualification and experience of construction planners are foundrnto be significantly influential to planning effectiveness. Furthermore it revealedrninadequate information gathering and ineffective method for planned informationrndissemination shadowed the construction planning practice in construction companies.rnThese necessitate the enhancement of construction companiesâ€™ commitment forrnconstruction planning phase and the need to keep construction planners qualified,rnupdated with proper training and use of up-to-date planning techniques.