Oncologic patients on opioid therapy due to pain may have several side effects, including respiratory depression (in about 1% of cases), pruritus (up to 10% of cases), nausea (in 25-32% of cases), sedation (in 20- 60% of cases); but the most far-reaching side effect (up to 95% of cases) that can occur is constipation. The socalled "opioid-induced constipation" (OIC) can develop at the start of opioid therapy and can last as long as continued use. The OIC is a real change in intestinal habits that occurs when opioid treatment is started; it is noted with a reduced frequency of episodes of defecation, with a development or worsening of the effort to defecation, with a feeling of incomplete emptying and a perception on the part of the patient to live in a stressful way the act of defecation. Also because of this, the OIC can induce to tolerate the dose of opioids routinely causing inadequate pain management. Continuous therapy with opioids lasting at least two weeks and resistance to the treatment of constipation with osmotic laxatives for more than three days in patients with terminal disease (Nota 90 AIFA) allow the prescription of naloxegol, a PEGylated derivative of the naloxone. Naloxegol belongs to the PAMORA family (peripheral mu-opioid receptor antagonists) which does not generally cross the blood-brain barrier and therefore does not interfere with the central nervous system-mediated analgesic efficacy. The reported clinical case tends to show how the use of the drug under examination (naloxegol) solves the problem of the OIC in a oncologic patient, improving her quality of life.