PURPOSE: Leptomeningeal metastasis (LM)-associated hydrocephalus is a rare but severe complication of non-small cell lung cancer (NSCLC). The spread of malignant cells to the leptomeninges obstructs cerebrospinal fluid flow and increases intracranial pressure (ICP). This study compared the outcomes of lumboperitoneal (LP) and ventriculoperitoneal (VP) shunt surgeries in managing LM-associated hydrocephalus, focusing on symptom-free periods (SFPs) and overall survival (OS). METHODS: A retrospective analysis was conducted on 43 NSCLC patients with LM-associated hydrocephalus who underwent shunt surgery between 2017 and 2024. Patients were classified into LP (n = 23) and VP (n = 20) groups. Clinical characteristics, surgical outcomes, and survival rates were analyzed using Kaplan-Meier survival and Cox regression analyses. Karnofsky performance status (KPS), increased intracranial pressure (IICP) symptoms, and postoperative epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) treatment were evaluated for prognostic significance. RESULTS: No significant difference was observed between VP and LP shunt surgeries regarding SFP (VP: 5.02 ± 1.29 months, LP: 7.50 ± 2.86 months, p = 0.906) or OS (VP: 8.43 ± 1.89 months, LP: 9.62 ± 3.20 months, p = 0.820). High preoperative KPS, absence of ICP symptoms, and postoperative EGFR-TKI treatment were significantly associated with improved SFP and OS (p <
0.05). LP shunt surgery had shorter anesthesia and fewer complications compared to VP shunt surgery, representing a viable option for patients unsuitable for general anesthesia. CONCLUSION: LP and VP shunt surgeries are equally effective for patients with LM-associated hydrocephalus in NSCLC. LP shunt surgery under local anesthesia could be recommended for its safety and patient acceptability. Favorable prognostic factors, including high KPS, absence of ICP, and postoperative EGFR-TKI treatment, should guide individualized treatment strategies to enhance patient outcomes and quality of life.