Delays are a common occurrence in the construction industry across the globe. The purpose of this study was to investigate the primary causes of construction delays and examine methods for minimizing delays in public projects in Kota Kinabalu using the RII method. Based on a review of secondary data, four categories were identified as contributing to the primary causes of construction delays, along with 50 causes of delay and 17 techniques for minimizing construction delays. Using IBM SPSS Statistics 26, the 140-survey data were analyzed and ranked by Relative Importance Index for each cause. The results indicate that poor communication and coordination, slowness in the decision-making process, unclear and insufficient detail in drawings, land and site problems, poor management and supervision of the site by the contractor, late payment, poor communication and coordination, and a delay in obtaining municipal permits were the primary causes of the delay. Proper planning prior to the start of the project is the most effective method for minimizing delay; regular coordination between the parties involved is required; and approved and confirmed design concepts, construction drawings, material selection, and logistics management must be in place well before construction.