Objective To investigate the roles of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) in the diagnosis and prognosis of intensive care unit-acquired weakness (ICUAW) in patients undergoing mechanical ventilation.Methods Seventy-five patients who were admitted to the department of critical care medicine in our hospital from July 2017 to June 2019 were divided into observation group (47 patients) and control group (28 patients). The observation group was subdivided into ICUAW cured group and ICUAW uncured group. Neuroelectrophysiological examinations were performed on the 3rd and 10th days after mechanical ventilation. The expression levels of TNF-α, IL-1β, and IL-6 were monitored, and their roles in the diagnosis and prognosis of ICUAW in patients undergoing mechanical ventilation were analyzed.Results The expression levels of TNF-α, IL-1β, and IL-6 on the 3rd and 10th days after mechanical ventilation in the observation group were significantly higher than those in the control group (P<0.05), and the expression levels of TNF-α, IL-1β, and IL-6 on the 10th day after mechanical ventilation in the ICUAW uncured group were significantly higher than those in the ICUAW cured group (P<0.05). There were no significant differences in the expression levels of TNF-α, IL-1β, and IL-6 on the 3rd day after mechanical ventilation between patients with critical illness polyneuropathy, critical illness myopathy, and critical illness myoneuropathy (P>0.05).Conclusions TNF-α, IL-1β, and IL-6 are associated with the development of ICUAW. Continuously increased TNF-α, IL-1β, and IL-6 suggest a poor prognosis in patients undergoing mechanical ventilation.