Purpose. To compare the efficacy of individualized herbal decoction with controlled decoction for individual patients with stable bronchiectasis.Methods. We conducted N-of-1 RCTs (single-patient, double-blind, randomized, multiple crossover design) in 3 patients with stable bronchiectasis. The primary outcome was patient self-rated symptom scores on visual analogue scales. Secondary outcome was 24-hour sputum volume. A clinical efficacy criterion which combined symptoms score and medication preference was also formulated.Results. All three patients showed various degrees of improvement on their symptoms and one patient’s (Case 3) 24 h sputum volume decreased from 70 mL to 30 mL. However, no significant differences were found between individualized herbal decoction and control decoction on symptoms score, or on 24-hour sputum volume. One patient (Case 2) had clear preference for the individualized herbal decoction over the standard one with the confirmation after unblinding. We therefore considered this case as clinically important.Discussion. N-of-1 trials comply with individualized philosophy of TCM clinical practice and had good compliance. It is necessary to set up clinical efficacy criteria and to consider the interference of acute exacerbation.