Diffuse esophageal spasm, an uncommon esophageal motility disorder, has recently been defined using high-resolution manometry. Patients with distal esophageal spasm usually complain of chest pain or dysphagia. The etiology and pathophysiology of this disorder are poorly known, and treatment options are limited. However, some options to improve symptoms are available, including endoscopic injection of botulinum toxin. Nevertheless, few reports have described the effects of endoscopic injection of botulinum toxin in patients with symptomatic diffuse esophageal spasm with clear endoscopic and high-resolution manometry images. Here, we report a case of diffuse esophageal spasm diagnosed with high-resolution manometry and treated by endoscopic injection of botulinum toxin with good results at the 7-month follow-up.