A number of traditional Chinese medicines (TCMs) are widely used in prostate cancer treatment in China. The aim of this study was to test the efficacy of a TCM, Zhoushi Qiling Decoction (ZQD), in combination with androgen deprivation therapy (ADT) and explore its underlying mechanism. A total of 151 patients were recruited to receive ADT treatment or ADT+ZQD treatment. The survival of patients who received ADT+ZQD treatment was significantly higher than those who received ADT therapy only. DU145 prostate cancer cells were treated with ZQD (50 mg/mL) for 24 h in vitro and expression levels of an array of miRNAs were examined. Our results suggested that miR-143 demonstrated prominent upregulation in DU145 cells after treatment with ZQD. In patient serum samples, miR-143 expression was also significantly upregulated after ADT+ZQE treatment, which was however absent in patients treated with ADT only. In DU145 cells, ZQD treatment led to a dose-dependent increase in apoptosis, which could be reduced by anti-miR-143 treatment. There was a binding site between miR-143 and B cell CLL/lymphoma-2 (Bcl-2) and ZQD treatment reduced Bcl-2 expression. ZQD treatment led to increased caspase-3 and Bax expression. ZQD treatment could promote apoptosis of prostate cancer cells by promoting miR-143 upregulation, which could be a possible mechanism underlying the inhibitory effect of ZQD in prostate cancer in patient.