Purpose Conflicts, claims and disputes are inherent in most construction projects. Acceptable degree of commonality in the interpretation of contract provisions is critical in effective contract administration. This study aims to assess the effects of contract ambiguity factors on construction conflicts, highlighting the causes of divergent interpretations using fuzzy technique for order of preference by the similarity-to-ideal-solution (TOPSIS) method. Design/methodology/approach Fuzzy TOPSIS framework with 27 ambiguity factors is constructed by conducting a comprehensive literature review, accompanied by a pilot study. Questionnaire survey is formed, and one-to-one interviews are arranged with 35 contract administration experts. Findings The findings indicate that (1) ambiguity due to excessive changes in the bill of quantity (BOQ) (including ambiguous provisions related to BOQ changes), (2) incomplete clauses that do not describe the scope of the intended work purely, (3) ambiguity due to excessive amendments in the scope of works (including ambiguous provisions related to scope changes), (4) ambiguous enforceability including excessive demands and (5) ambiguous goal and performance requirements are the top five ambiguity factors affecting construction conflicts. Research limitations/implications Presented framework is performed referring to ambiguity factors in all type of construction contracts in the general sense. However, the identified factors may vary depending on the project type, contract type, procurement method or use of standard contract forms (such as NEC, FIDIC). Originality/value The literature lacks the investigation of ambiguity factors in construction contracts, yet the assessment of the effects of contract ambiguity is essential to minimize conflicts.