BACKGROUND Transection of the cricopharyngeus muscle supposedly is of crucial therapeutic importance, because of its hypothesized pathogenic role in Zenker's diverticulum (ZD). This retrospective, nonrandomized study evaluates the outcomes of surgical therapy, with reference to cricopharyngeal myotomy (CM). METHODS Seventy-nine patients underwent diverticulectomy from 1985 to 1999. Group A (n = 47; men:women, 29:18; mean age +/- SD: 69 +/- 12 [range 35 to 87] years) underwent CM because of clearly discernible hypertrophic transverse fibers. In group B (n = 32; men:women, 22:10; mean age +/- SD 68 +/- 13 [range 36 to 95] years), without such transverse fibers, no CM was carried out. Dysphagia, regurgitation, and diverticular radiomorphology were classified according to ordinal scales. Diverticular volumes were calculated from barium swallows. Postoperative symptoms and outcomes were evaluated by questionnaires sent to the patients. RESULTS The two groups did not differ significantly in severity of preoperative dysphagia and regurgitation, radiomorphology, or median diverticular volume. Both groups experienced postoperative alleviation of symptoms (p < 0.001), persisting slightly in 11 of 47 (23%) group A and 4 of 32 (13%) group B patients (p > 0.05). Of these, seven group A (64%) patients and three group B patients (75%) had additional upper gastrointestinal tract (GIT) diseases. Recurrent diverticula occurred in one patient and postoperative complications in five patients per group (p > 0.05). Diverticular volume and upper GIT comorbidities, but not CM, were significant risk factors for persistent symptoms in the multivariate analysis. CONCLUSIONS CM has no significant influence on postoperative results, if carried out depending on the anatomic state and configuration of the cricopharyngeus muscle. This is suggested by the favorable outcomes of patients, with persistent symptoms being caused by factors other than CM.