Background: Trapped fourth ventricle (TFV) is a rare late complication of post-infectious or post-hemorrhagic hydrocephalus. It is a characteristic pathology of children that has rarely been described in adults. This entity is distinct from a large fourth ventricle because TFV entails pressure in the fourth ventricle and posterior fossa due to abnormal inflow and outflow of CSF, causing significant symptoms and signs. Case description: In the present paper, the authors describe the case of a 29-year-old man who presented with an isolated fourth ventricle. The neurological examination revealed instability, dysarthria, and an alteration in normal swallowing. The imaging was correlated with the clinic. The patient was operated on twice. The first time, a fenestration and 4-ventricle-cistern magna shunt were performed with improvement in the patient but with recurrence in the clinic later. In the second surgery, a 4-ventricle peritoneal valve was implanted, with improvement maintained over time. There are multiple approaches to isolated 4th ventricle surgery: endoscopic approaches, open microsurgical approaches, shunts, and hybrid approaches. The literature shows that both endoscopy and microsurgery are the two modalities with the best results and fewer complications. Between both, our choice is microsurgery given its versatility, although it depends a lot on the surgeon's experience. Conclusion: The surgical options (fenestration, more shunt ventricle-cistern magna, and shunt ventricle-peritoneal) are safe and effective alternatives in the treatment of trapped 4V with a very good long-term outcome and low rate of morbidity.