To assess the efficacy of bloodletting therapy (acupoint pricking and cupping) in patients with chronic idiopathic urticaria (CIU) in a randomized, control, parallel-group trial. A total of 174 patients with CIU enrolled from March 2018 to October 2019 were randomized into three groups: group A treated with bloodletting therapy and ebastine, group B treated with placebo treatment (acupoint pseudopricking and cupping) and ebastine, and group C treated with ebastine only. The intention-to-treat analysis was conducted, and the primary outcome was the effective rate of UAS7 score being reduced to 7 or below after treatment phase. The effective rates at the end of treatment phase were different among the three groups (P < 0.05), which were 73.7% in group A, 45.6% in group B, and 42.9% in group C. Multiple analysis indicated differences between groups A and B (P < 0.0125) and groups A and C (P < 0.0125) and no difference between groups B and C (P > 0.0125). No severe bloodletting therapy-related adverse events were observed. In this study on patients with CIU, one month of bloodletting therapy combined with ebastine is clinically beneficial compared with placebo treatment combined with ebastine and treatment with ebastine only. Thus, bloodletting therapy can be an effective complementary treatment in CIU. This trial is registered with ChiCTR1800015294. Copyright © 2020 Biru Ma et al.