Intractable conflicts between two individuals within an organization can be particularly detrimental, exerting ripple effects that affect other individuals, entire units, or the organization as a whole. This study extends previous research on third-party consultation interventions by exploring trust and other variables that facilitate intractable conflict resolution, while examining several outcomes over time. Data for this 14-year study in an operating room came from self-reports by the participants, behavioral observations by hospital administrators, and hospital records. Results include statistically significant improvement in trust measures, individual and group effectiveness, increased availability of surgical supplies and equipment, reduced physician abuse of scheduling privileges, decreased verbal abuse of nurses by physicians, the elimination of nursing turnover, and a decision by the surgeons to not build an outpatient surgical center. From a methodological standpoint, our quasi-experimental design using longitudinal panel data provide strong evidence for the effectiveness of organization development interventions on intractable conflicts, including not only how resolutions and positive outcomes occur but also how they can endure over time.