The nature and practice of stakeholder engagement has been discussed in the context of the UK construction industry. The industry is complex, fragmented; prone to change; has multiple stakeholders and thus the potential for conflicting stakes. The industry therefore needs to orient itself on the best approach to engage its stakeholder to achieve efficient contracting within a situational context of uncertainty. Qualitative research was use to investigate the nature and practice of stakeholder engagement within the private and public sectors of the industry. 21 interviews and one focus group discussion involving 9 participants were held. The interviews were divided into exploratory, investigative, validating and review interviews. The qualitative data was process by content analysis and cross case comparative analysis to identify key concepts and principles associated with the nature and practice of stakeholder engagement. The validating interviews together with the focus group discussion were used to verify the findings. A situational flexible theory of contingency stakeholder engagement that is adaptable to different situational context has been suggested