The management of chronic pain among patients with abdominal cancer is complex; against that, the neurolysis of the celiac plexus (CPN) is the best technique at the moment to determine the efficacy and safety in the treatment of chronic pain secondary to oncological pathology of the upper abdomen. This was a systematic review of controlled clinical trials between 2000 and 2021, in the sources MEDLINE/PubMed, Cochrane, Scopus, Web of Science, and Google Scholar. Three independent evaluators analysed the results of the bibliographical research. The quality of the studies was assessed with the Jadad scale and the mean difference (95% confidence interval) and heterogeneity of the studies (I2) were calculated with Review Manager 5.3. Seven hundred and forty-four publications were identified, including 13 studies in the qualitative synthesis and three studies in the quantitative synthesis. No difference was found in the decrease in pain intensity between 1 and 12 weeks after the intervention, comparing the experimental group with the control (P > 0.05). The adverse effects related to neurolysis were not serious and transitory, mentioning the most frequent adverse effects and reporting a percentage between 21% and 67% (with 17% for echoendoscopic neurolysis and 49% for percutaneous neurolysis). Celiac plexus neurolysis for the treatment of severe chronic pain secondary to oncological pathology in the upper hemiabdomen produces similar pain relief as conventional pharmacological analgesic treatment. It is a safe analgesic technique since the complications are mild and transitory.