Abstract This cross-sectional study aimed to investigate the relationship between length of stay and different dimensions of patient satisfaction based on the SERVQUAL model. This study included 2,587 inpatients from forty-two clinical departments in a tertiary hospital in western China by using systematic sampling in each department. Data involving patient satisfaction, length of stay, sociodemographic characteristics and information about hospital visits of theses inpatients were collected and analyzed. Multilevel logistic regression modeling was performed to explore the adjusted relationship between length of stay and patient satisfaction at different dimensions. After controlling for covariates, the results showed that compared to patients who were hospitalized for less than or equal to two days, the satisfaction rate of tangibles and reliability both declined in patients with longer length of stay (3–6 days, 7–10 days, greater than or equal to 11 days) (all P 0.05). The research findings indicate that to enhance patient satisfaction, it is crucial to take measures to cater to the requirements of patients at various stages of their hospital stay, particularly by consistently ensuring the tangibility and reliability of service quality, and paying attention to empathy for patients with a hospital stay of 7 to 10 days.