Conflict is inevitable in service organizations because of task interdependence, customer expectations, workload pressures, role ambiguity and competition for organizational resources. This study examined the effects of conflict resolution strategies on organizational growth and productivity in Nigerian service firms, with particular attention to employee satisfaction, team cohesion and innovation climate as organizational process mechanisms. Anchored on the Thomas-Kilmann Conflict Mode framework and the Resource-Based View, the study adopted a quantitative cross-sectional design and analysed 210 observations from HR managers, supervisors and team leads in banking, telecommunications, hospitality, healthcare and logistics firms located in Lagos, Abuja, Port Harcourt, Kano and Enugu. Conflict resolution was operationalized through collaborating, compromising, avoiding, competing and accommodating strategies. PLS-SEM results showed that collaboration significantly predicted organizational growth (β=.42, t=6.87, p<.001, f²=.21), while compromise also had a positive effect (β=.28, t=4.31, p<.001, f²=.09). Avoidance (β=-.35, t=5.92, p<.001, f²=.15) and competition (β=-.22, t=3.84, p<.001, f²=.06) negatively predicted productivity. Organizational growth and productivity recorded R² values of .48 and .51 respectively, with Q² values of .42 and .45. PROCESS mediation results indicated significant indirect effects through team cohesion, employee satisfaction and innovation climate, while sector significantly conditioned selected strategy-outcome relationships. The study concludes that constructive conflict management is an organizational capability associated with stronger human processes, growth and productivity. Managers should institutionalize collaborative problem-solving, strengthen conflict-management competencies and adapt interventions to sector conditions.