Claims in the construction industry are a crucial element of project management and contract administration, with the potential to significantly impact project timelines, costs, and stakeholder relationships. Understanding the nature and causes of construction claims is vital for mitigating disputes and ensuring successful project delivery. This study delves into and assesses the causes of construction claims in the public construction industry in Palestine and identifies the parties responsible for these claims. A mixed-methods approach was used, combining qualitative interviews and quantitative questionnaires. Thirty-five causes of claims were identified through literature review and expert interviews. Descriptive statistics were employed to analyze the data, ranking the causes by significance index and assigning responsibility. The results indicated that contractors are responsible for approximately 50% of the identified causes of claims, followed by owners at 28% and designers at 22%. Furthermore, the results revealed that the three most significant causes of claims are poor management processes by contractors, work suspension due to the owner's non-compliance with contract requirements, and attempts by contractors to increase the quantities of certain work items. The findings offer helpful perspectives for all key players in public construction projects, serving as guidelines to minimize disruptions and enhance project outcomes.