Abstract: Construction projects have a prominent role in the growth and development of the private sector in the Kingdom of Bahrain. Claims and disputes in construction projects are one of the most prominent problems that have begun to surface clearly and can be defined as non-fulfillment by one of the parties to the agreed requirements of the contract and the rejection of the requirements of the other party, resulting in a claim for compensation resulting from that damage. The aim of this research is to investigate the causes of claims and disputes and their impact on construction projects in the private sector in the Kingdom of Bahrain, in addition to searching for strategies that can contribute to reducing the effects of these claims and disputes. The literature review was used to determine the main causes and effects. The method of the research was a mix of quantitative and qualitative methods that had been adopted by preparing a questionnaire and distributing it to real estate companies, engineering offices, and contractor individuals of a target population of 134 to identify the causes and impact of claims and disputes. In addition, in-depth interview was conducted with the company's managers and engineers. Accordingly, the data that had been received from 102 responses with a 76.1% response rate has been analyzed using the SPSS program by conducting tests such as Chi-Square, Descriptive Statistic, and Relative Importance Index. The results of the research showed a disagreement of points of view among the three categories (real estate companies, consulting offices, and contractors) in some parts and agreement in other parts regarding the causes and effects of claims and disputes on construction projects. The main and secondary reasons have already been identified, such as those related to the contractor, the owner, the project, the delay in site handing over, the reasons related to the consultant, the reasons related to human behavior, the external factors, and the contract. On the other hand, the effects of claims and disputes were identified and arranged based on their severity, such as the effects of cost overruns, time overruns, impact on human emotion, lack of trust and cooperation aspects, and low reputation. Identifying the main causes and their impact helped in understanding the problem. In a deeper way, thus reaching basic strategies to reduce the impact of disputes. Finally, the importance of this research lies in its role in seeking to remedy this issue within the huge construction projects in the Kingdom of Bahrain. The research concluded with a set of recommendations to improve the current situation, in addition to recommendations for future research.