This study aimed to assess the effect of individualized enteral nutrition management based on the prognostic nutrition index (PNI) on surgical patients with oral malignancies. This quasi-experimental pilot study consecutively included patients diagnosed with oral malignancies who underwent radical surgery in Ningbo No. 2 Hospital between January 2020 and May 2023. The primary outcome was PNI. A total of 71 patients with oral malignancies were enrolled, and 35 patients received PNI-based individualized enteral nutrition management. The PNI group displayed significantly higher PNI than the routine enteral nutrition support group (1st week postoperatively: 39.86 ± 3.86 vs. 37.29 ± 4.23, p < 0.001. 2nd weeks postoperatively: 44.17 ± 4.36 vs. 40.72 ± 3.40, p < 0.001). The surgical suture removal time and length of hospital stay (both p < 0.001) in the PNI group were significantly shorter than in the routine enteral nutrition support group. At 1 month postoperatively, the PNI group had significantly higher scores of QoL (p = 0.002) than the routine enteral nutrition support group. The individualized enteral nutrition management based on the PNI could improve the nutritional status of postoperative patients with oral malignancy, which could facilitate postoperative rehabilitation and improve overall QoL.