OBJECTIVE The primary strategy for treating oral squamous cell carcinoma (OSCC) is therapeutic resection, with the trismus resection defect reconstructed via free flap. The most popular free flaps include the radial forearm free flap (RFFF) and anterolateral thigh free flap (ALT). This study investigated the relationships between the hospitalization period and a variety of surgical outcomes, as well as maximum inter-incisor distance (IID), in trismus patients who chewed betel nuts. METHODS Forty-nine primary OSCC patients who chewed betel nuts and underwent surgical resection and reconstruction between 2010 and 2016 were enrolled in this retrospective study. The data were from a single center in Taiwan. The outcome variable after flap recovery surgery was the duration of postoperative hospitalization. Other factors that were analyzed comprised correlations between hospitalization and a variety of factors, including postoperative inter-incisor distances (IIDs), operative time, gender, and WBC count, upon stratification into two reconstruction groups. RESULTS The mean postoperative hospitalization duration in the ALT group was 22.9 ± 7.2 days, which was significantly shorter than that in the RFFF group (27.8 ± 7.0 days; p = 0.019). Two-week postoperative IID (ALT group: 16.1 ± 0.8 mm; RFFF group: 7.0 ± 0.6 mm) was inversely related to the duration of hospitalization (p = 0.022, r = - 0.372). CONCLUSIONS The ALT flap is more effective than the RFFF flap to reduce the length of hospitalization in trismus patients. CONCLUSIONS The ALT flap should be considered as a first-line technique in OSCC reconstruction in trismus patient reconstruction.