Purpose　The　purpose　of　this　paper　is　to　examine　the　influence　of　clients＇　trust,　opportunism　and　adaptation　on　contractual　(non)cooperation　with　a　mediating　role　of　coordination　in　the　construction　industry.　Design/methodology/approach　A　questionnaire　was　used　to　collect　data　from　employees　of　the　Pakistani　construction　industry.　Smart　partial　least　square　(SmartPLS)　has　been　used　for　analyzing　the　data　of　270　respondents　from　construction　projects.　Findings　The　results　of　the　SmartPLS　indicate　that　(1)　Trust　and　contract　coordination　positively　while　opportunism　negatively　influence　contractor＇s　contractual　cooperation.　(2)　Contract　adaptation　and　contract　coordination　positively　influence　the　noncontractual　cooperation　of　the　contractor.　(3)　Moreover,　contract　coordination　positively　mediates　the　relationship　between　trust　and　noncontractual　cooperation,　but　negatively　mediates　the　relationship　between　opportunism　and　contract　adaptation　and　noncontractual　cooperation.　Practical　implications　The　findings　of　this　research　suggest　several　policy　implications　for　administrative　authorities,　project　managers　and　policymakers.　These　authorities　need　to　focus　on　clients＇　trust,　opportunism　and　adaptation　because　these　factors　significantly　influence　contract　coordination　and　cooperation　in　the　construction　industry.　Emphasizing　these　factors　will　enable　project　managers　to　gain　economies　of　scale　and　mitigate　project　failure.　Originality/value　To　the　best　of　the　authors＇　search　and　knowledge,　they　did　not　find　any　study　examining　the　mediating　role　of　coordination　between　trust,　opportunism,　adaptation　and　cooperation　in　the　construction　industry.　Hence,　the　present　study　advances　their　understanding　in　the　field　of　project　management　and　construction　business.