Background and study aims Epiphrenic diverticula are rare and mainly occur in patients with underlying esophageal motility disorders. The current standard treatment is surgical diverticulectomy often combined by myotomy and is associated with significant adverse event (AE) rates. The aim of this study was to examine the efficacy and safety of peroral endoscopic myotomy in reducing esophageal symptoms in patients with esophageal diverticula. Patients and methods We performed a retrospective cohort study including patients with an esophageal diverticulum who underwent POEM between October 2014 and December 2022. After informed consent, data were extracted from medical records and patients completed a survey by telephone. The primary outcome was treatment success, defined as Eckardt score below 4 with a minimal reduction of 2 points. Results Seventeen patients (mean age 71 years, 41.2 % female) were included. Achalasia was confirmed in 13 patients (13 /17, 76.5 %), Jackhammer esophagus in two patients (2 /17, 11.8 %), diffuse esophageal spasm in one patient (1 /17, 5.9 %) and in one patient no esophageal motility disorder was found (1 /17, 5.9 %). Treatment success was 68.8 % and only one patient (6.3 %) underwent retreatment (pneumatic dilatation). Median Eckardt scores decreased from 7 to 1 after POEM (p < 0.001). Mean size of the diverticula decreased from 3.6 cm to 2.9 cm after POEM (p < 0.001). Clinical admission was one night for all patients. AEs occurred in two patients (11.8 %) which were classified as grade II and IIIa (AGREE classification). Conclusions POEM is effective and safe to treat patients with esophageal diverticula and an underlying esophageal motility disorder.