Background and Aim The treatment of patients with functional dyspepsia (FD) remains unsatisfactory. We assessed the efficacy of Zhizhu Kuanzhong (ZZKZ) capsule, a traditional Chinese medicine formula, in patients with postprandial distress syndrome (PDS) of FD. Methods The study was designed as a multicenter, randomized, double-blinded, controlled clinical trial. Three-hundred ninety-two patients with PDS defined by Rome III criteria from 16 centers in China were randomly assigned to receive either ZZKZ or placebo. The proportion of the responders at 4 weeks after randomization was considered primary endpoint. Secondary endpoint was the symptom score reduction of each dyspeptic symptom relative to the baseline at 4 weeks after randomization in all subjects. Results In terms of the primary endpoint, the proportion of the responders concerning the composite PDS symptom score was 38.8% and 54.7% in placebo group and ZZKZ group, respectively (P = 0.003), in per protocol analysis at 4 weeks after randomization. Concerning the individual evaluated upper gastrointestinal symptoms, only postprandial fullness and early satiety showed significant difference in symptom score reduction at 4 weeks after randomization between placebo and ZZKZ groups. Conclusions Zhizhu Kuanzhong is superior to placebo in the treatment of PDS with FD. The exact mechanisms by which ZZKZ improves symptoms remain to be established ().