The present study compares the efficacy of a self-expanding metallic stent (SEMS, diameter of 30 mm) and pneumatic dilation for the long-term clinical treatment of achalasia. A total of 155 patients diagnosed with achalasia were allocated for pneumatic dilation (n= 80, group A) or a temporary, 30-mm diameter SEMS (n= 75, group B). The SEMSs were placed under fluoroscopic guidance and removed by gastroscopy 4-5 days after placement. Data on clinical symptoms, complications, and long-term clinical outcomes were collected, and follow-up observations were performed at 6 months and at 1, 3-5, 5-8, 8-10, and >10 years, postoperatively. Pneumatic dilation and stent placement were technically successful in all of the patients. There were no significant differences in technique success, 30-day mortality, or complications between the two groups. The clinical remission rate in group A was significantly lower than that in group B at 1, 1-3, 3-5, 5-8 and, >10 years (P < 0.05), while the cumulative clinical failure rate in group A (66%, 53/80) was higher than that in group B (92%, 6/75). The mean primary patency in group B was significantly longer than that in group A (4.2 vs 2.1 years, respectively; P < 0.001). A temporary, 30-mm diameter SEMS was associated with a better long-term clinical efficacy in the treatment of patients with achalasia as compared with treatment with pneumatic dilation.