Lennox-Gastaut syndrome (LGS) is a severe form of drug-resistant epilepsy that begins during childhood and frequently leads to significant neurological impairments. Patients with LGS are likely to receive improper oral nutrition because of issues such as dysphagia and aspiration risk, potentially resulting in long-term tube feeding and eventual gastrostomy tube placement. Therefore, we investigated the effects of gastrostomy tube placement on nutrition outcomes and frequency of hospitalization in LGS. We retrospectively examined 67 patients diagnosed with LGS who had undergone gastrostomy tube placement between January 2005 and August 2022. Comprehensive clinical data and complications arising from the procedure were collected. Patients' nutrition condition and frequency of hospitalizations were analyzed before and after gastrostomy tube placement. Gastrostomy tube placement was performed for the following reasons: high risk of aspiration (50 out of 67, 74.6%), dysphagia (13 out of 67, 25.4%), persistent nasogastric tube feeding (2 out of 67, 3.0%), and severe malnutrition (2 out of 67, 3.0%). After the procedure, z scores for weight-for-age improved significantly, shifting from -3.35 ± 3.57 to -2.54 ± 2.70 over a 2-year interval (P < 0.001). Additionally, the total days of hospitalization and days of hospitalization due to respiratory symptoms reduced significantly from 41.94 ± 51.76 to 15.27 ± 26.68 (P < 0.001) and from 23.75 ± 36.92 to 10.52 ± 22.98 (P = 0.009), respectively. Among the patients, 50 (74.6%) experienced complications resulting from gastrostomy, with a relatively small proportion of major complications (11 out of 67, 16.4%) and no mortality. Gastrostomy tube placement is a relatively safe procedure with favorable effects on nutrition status and hospitalization rates in patients with LGS.