Pancreatic cancer patients experience debilitating pain, which makes pain management an integral part of the treatment plan. Endoscopic ultrasound-guided celiac plexus neurolysis (EUS-guided CPN) is an alternative palliative therapy for patients with pain due to pancreatic cancer. We report a patient who developed paralytic ileus after undergoing EUS-guided CPN. A 77-year-old male patient presented with nausea, vomiting, and abdominal pain of one-day duration. He was diagnosed with stage IV pancreatic adenocarcinoma three weeks prior to presentation for which he underwent EUS-guided CPN. He had a 30-pack-year smoking history and quit 31 years ago. He reported moderate alcohol use and denied illicit drug use. In the emergency department, vital signs demonstrated normal blood pressure, heart rate, respiratory rate, and temperature. Abdominal exam was significant for minimal epigastric tenderness without guarding or rebound. Complete blood count (CBC), basic metabolic panel (BMP), and liver function tests were unremarkable. Computed tomography (CT) scan of the abdomen showed significant gastric distension. Esophagogastroduodenoscopy (EGD) showed large amounts of fluids within the gastric fundus and body. Upper gastrointestinal series showed delayed gastric emptying of the contrast, but contrast was seen in the third part of the duodenum and jejunum. Push enteroscopy showed no obstruction or mucosal abnormalities in the third or fourth parts of the duodenum. Small bowel obstruction was ruled out, and the diagnosis of ileus was made. The patient received ondansetron and polyethylene glycol as needed, and his diet was advanced slowly. His symptoms improved over the course of a few days, and he experienced a return of normal bowel activity. He eventually tolerated a regular diet and was discharged home in a stable condition. Although EUS-guided CPN is a safe procedure, the procedure resulted in an unexpected ileus that has rarely been reported in the literature. Future studies with large sample sizes are recommended to capture the occurrence of the rare side effects of EUS-guided CPN.