Objective To research the expression of liver kinase B1 (LKB1) in nasopharyngeal carcinoma (NPC) tissues and analyze its relationships with clinicopathological parameters, chemosensitivity and prognosis. Methods The expression of LKB1 in 74 NPC tissue samples was detected by EnVision two-step immunohistochemical assay, and then the NPC tissue samples were divided into the LKB1 low-expression group and the LKB1 high-expression group. The in vitro chemosensitivity of NPC cells to 8 common chemotherapeutic drugs was detected by ATP-fluorescence in vitro susceptibility assay. Combined with follow-up data of the patients, the relationships of the expression of LKB1 with clinicopathological parameters, chemosensitivity and prognosis were analyzed. Results LKB1 was expressed in both nuclei and cytoplasm in the NPC cells, showing a brownish yellow color. There was no significant difference in the age, histopathological type, TNM stage or clinical stage between the two groups (P > 0.05); but there was statistical difference in gender between the two groups (P < 0.05). The chemosensitivity of NPC cells to the 8 chemotherapeutic agents was different (P < 0.05). The rate of resistance to cyclophosphamide in the LKB1 low-expression group was higher than that in the LKB1 high-expression group (P < 0.05), and the rates of resistance to the remaining drugs were not statistically different between the two groups (P > 0.05). The mortality of the LKB1 low-expression group was higher than that of the LKB1 high-expression group (P < 0.05). There was no significant difference in metastasis or recurrence rate between the two groups (P > 0.05). The overall survival rate of the patients in the LKB1 low-expression group was lower than that in the high-expression group (P < 0.05), but there was no significant difference in the progression-free survival rate between the two groups (P > 0.05). Conclusions Low expression of LKB1 is related to the survival rate of NPC patients and may be related to the resistance to cyclophosphamide.