Objective To investigate the correlation between prognostic nutritional index PNI and insulin resistance IR in male patients with fatty liver disease and to provide a scientific basis for the clinical management of patients with fatty liver disease. Method A cross-sectional survey Method was used to analyze the data from male individuals who underwent health examinations at the Health Management Center of the Affiliated Hospital of Southwest Medical University between January 2019 to December 2021 and fatty liver was diagnosed based on abdominal ultrasound results. IR was defined according to the triglyceride-glucose index TyG and PNI scores were categorized into tertiles Q1 PNI < 55. 36 Q2 55. 36 ≤ PNI < 58. 56 Q3 PNI ≥58. 56 . Logistic regression analysis was employed to examine the association between PNI and IR with the Q1 group serving as the reference. Result A total of 714 male patients with fatty liver were included in this study of which 490 had IR 68. 63% . The results of univariate and multivariate logistic regression analysis showed that PNI is a risk factor for IR in male patients with fatty liver disease. Univariate logistic regression analysis compared with the PNI < 55. 36 group the risk of IR when PNI levels were 55. 36 ≤ PNI < 58. 56 and PNI ≥ 58. 56 increased by 1. 717 times and 2. 264 times greater respectively. Multivariate logistic regression analysis after adjusting for confounding factors such as body mass index waist circumference visceral fat area and total cholesterol compared with the PNI < 55. 36 group the risk of IR when PNI levels were 55. 36≤ PNI < 58. 56 and PNI≥58. 56 increased by 1. 694 and 1. 710 times respectively. Conclusion PNI may serve as a useful indicator for assessing the risk of IR in male patients with fatty liver and may potentially be a predictor of IR onset.