Construction delays are a relentless issue for the world. The majority of construction projects retrograde due to construction delays. However, the construction sector possesses the most essential priority among various sectors as it enables the economy to flourish. This study aims to explore the most crucial causes that highly affect construction projects and delay their completion in the Pakistani construction industry, comparing explored factors with other countries in Asia. This study identified forty-nine factors after reviewing past literature and redefining them through interviews with Pakistani field experts. Later, categorized into eight groups, such as investor perspective, constructor perspective, advisor perspective, financial issues, planning and budgeting, coordination with stakeholders, determinants of construction projects, and miscellaneous factors, to interrogate public and private contractors and consultants through a structured questionnaire. The relative importance index (RII) approach empirically validated the study objectives with an aggregate sample of 330 responses. Statistical analysis of the accumulated data through the survey revealed ten major factors based on constructor and consultant perception that cause delays and affect the on-time completion and performance of the construction work. Thus, this study presents recommendations for the practitioners and parties associated with the construction sector of Pakistan to minimize the influence of the observed factors on construction projects.