Understanding the behavioural and physiological responses of large pelagic species to recreational angling is critical for informing conservation practices and reducing post-release mortality. In this study, we analysed high-resolution temperature, depth, and acceleration data from ten swordfish (Xiphias gladius) during recreational angling events to investigate their stress responses and thermoregulatory behaviour. All individuals exhibited distinct, repeatable behavioural phases: initial bait interaction, rapid ascent post-hookup, sustained resistance, and eventual exhaustion. Notably, immediately after hook-up, each swordfish initiated a vertical ascent toward the surface, suggesting a common acute stress response. During the resistance phase, individuals often engaged in prolonged stalemates, maintaining position near their respective thermocline depths - a potential behavioural strategy for managing thermal and metabolic stress. The final exhaustion phase was marked by reduced activity levels and increased time at depth, likely reflecting physiological fatigue. These behavioural patterns reveal both species-specific strategies for stress mitigation and the ecological significance of thermal habitat use during angling events. Our findings contribute to a more nuanced understanding of capture stress in pelagic fishes and highlight the importance of fine-scale behavioural monitoring. These insights can be directly applied to the development of best-practice guidelines for recreational swordfish fisheries, with the goal of reducing unnecessary mortality and improving post-release survival.