PurposeThe study examines the project success factors for leadership behavioural practices and communication impacting project success, providing empirical evidence to address the challenges in the digitalized environment in the Australian construction sector.Design/methodology/approachA quantitative approach was employed to collect survey data from 109 project managers and followers (project engineers, supervisors, team members, and senior managers) with diverse project management experience in the construction sector. An exploratory factors analysis/multivariate regression/relative importance index/t-test was used to identify the key project success factors and validate the study's results.FindingsData analysis identified four key project success factors: (1) Relationship Management, (2) Leading by Example, (3) Self-Management, and (4) Effective Communication, along with seventeen “behavioural practices attributes” impacting project success positively and significantly and emphasizing inclusiveness, relationship building, self-feedback objectivity, sharing information, collaboratively resolving disputes, and controlling emotions that significantly impact project success.Practical implicationsThe study's results will address the industry's challenges in the complex digitalized environment and specific issues experienced in the construction industry: delays and inefficiencies, supply chain management, communication barriers with multicultural workforce and safety protocols implementation, regulatory and safety compliance, infrastructure demands, skills shortages, sustainability, and new technology adoption to achieve project success.Originality/valueThe quantification of research findings, employing an innovative approach, underscores the distinctive nature of this study. The key success factors will help formulate innovative practices using stakeholder analysis, communication plans, conflict resolution strategies, promoting collaboration, safety leadership, providing cultural awareness, and enhancing the decision-making process to face challenges in the construction sector.