This article examines the antitrust issues in rural hospital mergers by focusing on an important antitrust case involving the merger of two small hospitals in Ukiah, California. A key issue in this matter was whether the geographic market served by the merger included a nearby larger city. The economic efficiency of small rural hospitals and the competitive implications of their mergers are examined in the context of the Ukiah case. Economies of scale are shown to be important for small rural hospitals and should mitigate any increase in price. The efficiencies defense is shown to be difficult to make even when economies of scale make the likelihood of efficiencies high. The financial difficulties of many rural hospitals, especially in areas where too many exist, mean that mergers such as this one in Ukiah often are an efficient way to keep these hospitals financially sound and accessible. The Ukiah case suggests the desirability of the merger guidelines that permit most mergers of small rural hospitals.