To compare safety and effectiveness of prolonged (>28 days) versus short duration (≤28 days) use of nasogastric tube for enteral nutrition and weight loss prevention during curative radiotherapy with or without concurrent chemotherapy or cetuximab for head and neck cancer patients. We performed a retrospective study and database review of all patients at our center, treated with radiotherapy for head and neck cancer receiving enteral nutrition by nasogastric tube. Type of treatment, weight and body mass index changes, and related complications (gastroesophageal reflux, pneumonia, ulcer, feeding tube obstruction, or dislocation) were documented. Comparison between patients with prolonged (>28 days, group A) and short duration (≤28 days, group B) of EN through nasogastric tube was performed. Data expressed as mean ± SD or median (min; max) values as appropriate, and analyzed by ANOVA repeated measures and Kaplan-Meier estimates. We identified 114 patients who fulfilled the inclusion criteria. Among them, 10% were treated with radiotherapy alone, while 90% received concurrent chemotherapy or cetuximab. Ninety-four patients (82%, group A) had a nasogastric tube in place for a period >28 days and 20 (18%, group B) for ≤28 days during treatment. Patients were mainly men (86 patients, 75%), with a median age of 61 years (range 49–73) and advanced stage IV disease in most cases (87 patients, 76%) without differences between both groups (p = 0.53, 0.47, and 0.30, respectively). Treatment discontinuation did not occur within both groups. Fifty-six patients (49%) developed complications, without a significant difference between both groups (P = 0.23). Body weight and BMI changes did not differ during EN (–0.8 ± 4.5 and –0.3 ± 1.6), the oncological treatment (–5.3 ± 4.0 and –1.8 ± 1.4), or 6 months after the end of treatment (–0.6 ± 4.4 and –0.2 ± 1.5). Our findings suggest that prolonged enteral nutrition by nasogastric tube is safe and effective in preventing weight loss during curative radiotherapy or radio-chemotherapy for head and neck cancer