Objective To investigate the diagnosis and treatment of long-standing overt ventriculomegaly in adults (LOVA).Methods The clinical features, diagnosis, treatment, and prognosis of 17 patients with LOVA admitted to the Department of Neurosurgery in our hospital were analyzed retrospectively.Results Among the 17 cases, the male/female ratio was 1.4:1 (10 males and 7 females), with a mean age of 46.3 years (range 27-58 years). The main clinical manifestations were headache (100%) and cognitive disorder (72.22%, 13 cases). The 17 cases underwent 21 times of surgery, were followed up for 6 months to 8 years, and showed varying degrees of improvement in symptoms. There were no deaths reported. Four cases underwent differential pressure valve (DPV) ventriculoperitoneal shunt, and three cases were aggravated after operation and needed to be converted to pressure-programmable valve (PPV) ventriculoperitoneal shunt. Each case treaded by PPV ventriculoperitoneal shunt underwent pressure adjustment at least three times. Eight cases underwent endoscopic third ventriculostomy (ETV), and one case had subdural hematoma after operation, which was removed by percutaneous external drainage.Conclusions LOVA is a special form of hydrocephalus and needs strict preoperative assessment. The surgical procedure should be PPV ventriculoperitoneal shunt or ETV.