Despite investment into fostering startup development, between 50-95 percent of new businesses fail in their first years, conflicts in startup teams and effects of work stress being two of the top reasons for this failure. However, the dynamics of stress, conflict, and decision-making in startup teams are hardly studied. This project aims to: (1) study startup team dynamics by integrating different aspects of stress (psychological, physiological), conflict, and regulatory efforts (e.g., stress and conflict coping) in real startup teams;and (2) study how the “wear and tear” of the startup social regulatory system (i.e., social allostatic load) can impair decision-making, relationship quality, and wellbeing of the team members, and, in the long term, hinder startup outcomes (e.g., survival). We integrate research on stress, conflict and team dynamics with management research, contributing to the constructive use of conflicts and promoting well-being, performance, and startup success.