Flood-induced damage to infrastructure poses significant economic and social challenges, particularly in disaster-prone regions. Reconstruction of damaged structures is often plagued by delays, leading to cost overruns, reduced quality, and loss of public trust. This study investigates the primary causes of delays in the reconstruction of flood-damaged structures in Gilan Province, Iran, a region frequently affected by severe flooding. Using a mixed-method approach, 19 qualified professionals (contractors, consultants, and employers) were surveyed with a 19-item questionnaire. Cronbach’s alpha (0.886) confirmed high reliability. Descriptive statistics and frequency analysis revealed that untimely allocation of funds and international economic instability/inflation are the most critical delay factors. Conversely, adverse weather conditions had the least impact, a finding contrary to many international studies. Other moderate-impact factors included deficiencies in initial design, excessive material harvesting, and lack of laboratory equipment. The study provides practical recommendations for improving financial mechanisms, inter-organizational coordination, and project risk management in post-disaster reconstruction.