Background This study was designed to examine the efficacy of Chinese herbal medicine (CHM) in the treatment of chronic rhinosinusitis (CRS) without nasal polyps. Methods Patients with CRS without nasal polyps were enrolled in the study. Before treatment, they were evaluated by the Taiwanese version of the 20-item Sino-Nasal Outcome Test (TWSNOT-20), nasal endoscopy, saccharin test, and bacterial culture. Then, they were randomized to take CHM (Tsang-Erh-San extract granules and Houttuynia extract powder) or erythromycin for 8 weeks. After treatment, they were evaluated again by the TWSNOT-20, nasal endoscopy, saccharin test, and bacterial culture. Results Fifty-three patients completed the study with 26 in the CHM group and 27 in the erythromycin group. In both the CHM and the erythromycin groups, TWSNOT-20 scores significantly decreased after treatment, but the decrease was not significantly different between the two groups. However, the saccharin transit times were shortened in more patients in the CHM group than in patients in the erythromycin group. Conclusion Our results showed CHM had an efficacy similar to that of macrolides in the treatment of CRS without nasal polyps. However, a placebo effect remained possible in both treatment groups.