This thesis investigates the role of external stakeholder management in fostering resilience within infra-structure projects, focusing on the complexities arising from interactions between stakeholders and pro-ject organizations. The research problem centres on how different stakeholder management strategies affect project resilience, especially in challenging environments.

To address this problem, a qualitative single-case study methodology was used, examining the "Tunel Diamante" project in Acapulco, Mexico. This approach allowed for an in-depth exploration of 26 events involving external stakeholders, such as government entities and landowners, to determine how their influence strategies and the project’s responses affect project resilience.

From the analysis, the thesis identified three primary traditional influence strategies employed by ex-ternal stakeholders: 'progress obstruction,' 'protest,' and 'demand for compromise.' Additionally, it in-troduced two innovative categories: 'collateral events' and 'proactive mitigation.' These latter strategies indicate a broader and more nuanced understanding of stakeholder influence.

The project adopted four response strategies: resourcefulness, dialogue and negotiation, coercive nego-tiation, and ignoring. These influenced the type of resilience, from absorptive to adaptive and trans-formative. Resourcefulness, characterised by adaptability, was linked to all types of resilience, while dia-logue and negotiation generally led to absorptive resilience. Coercive negotiation had mixed results, raising ethical concerns.

The findings suggest that stakeholder management strategies can significantly impact project resilience but may involve trade-offs and ethical considerations. This thesis contributes to the discourse on resili-ence in project management and offers practical insights into how external stakeholder management strategies shape resilience. It concludes that proactive and ethical stakeholder management is crucial for achieving sustainable project resilience, emphasising the importance of engaging stakeholders early and addressing their concerns constructively.