Purpose: Head and neck cancer (HNC) patients experience various posttreatment side effects that decrease quality of life (QOL). Some previous study reported that QOL of HHC patients were returned baseline (before treatment) after a year post treatment. However, acute stage longitudinal changes of QOL in HNC patients remains unclear. This point might be important for early reintegration of HNC patients. This study aimed to investigate the acute stage longitudinal change of the relationship between QOL and oral function in HNC patients had surgery. Methods: 45 HNC patients (23 men) scheduled for surgical treatment were enrolled in this study. Primary tumor sites were 22 tongue, 5 maxilla, 4 mandible, 3 pharynx and others. Weight, body mass index (BMI), whole body soft lean mass (SLM), and skeletal muscle mass (SMM) were evaluated as muscle mass-related measurements. Lip closure force (LC) and tongue pressure (TP) were evaluated as oral function measurements. Feeding function was evaluated using the Functional Oral Intake Scale (FOIS). QOL was assessed using the European Organization for Research and Treatment of Cancer QOL Questionnaire QLQ-C30 and H&N 35. Measures were evaluated at pre-surgical treatment (PT), and 1 month (1M) and 3 months (3M) after surgery. The change of QOL parameters and relationships between measurements were assessed. Results: For QOL assessments, role functioning, fatigue, speech problems, trouble with social eating, trouble with social contact, and opening mouth significantly decreased from PT to 1M, but significantly increased from 1M to 3M. Weight, BMI, SLM, SMM, LC, TP, and FOIS demonstrated significant relationships with QOL from PT to 1M. Meanwhile, from 1M to 3M, weight, BMI, SLM, SMM, LC, and FOIS showed significant relationships with QOL assessments. Conclusions: Both oral function and muscle mass-related measurements significantly affected QOL in HNC patients.