Planning comes first and is considered the most important stage in managing construction projects. This research aims to develop a Preconstruction Plan Index (PPI) as a subjective tool to assess the efficiency of the project plan prior to construction. The Delphi Technique was used to identify the most important factors based on the preferences of a panel of experts. The Analytical Hierarchy Process (AHP) assigned relative weights to 15 selected factors. Based on a proposed rating scale for each factor, the percentage of error in the plan is identified and a rating of the plan is obtained. The motive for developing PPI is to help construction practitioners assess the suitability of the proposed plan for the specific project requirements. Evaluation of the proposed PPI was achieved using two real case studies, for which results showed that the suggested PPI provided a satisfactory assessment tool for preconstruction planning.