Objective To investigate the characteristics of pan-immune-inflammation value （PIV），non-high-density lipoprotein cholesterol （non-HDL-C），and interleukin （IL） spectrum and their correlation with the severity of neurological function impairment in elderly patients with acute ischemic stroke. Methods A retrospective analysis was performed for 158 elderly patients with acute ischemic stroke who were hospitalized in our hospital from October 2019 to October 2024，and according to the severity of neurological function impairment，they were divided into non-severe neurological function impairment group with 112 patients and severe neurological function impairment group with 46 patients. The two groups were compared in terms of general clinical data，PIV，non-HDL-C，and ILs. A logistic regression analysis was used to investigate the risk factors for severe neurological function impairment in elderly patients with acute ischemic stroke，and the receiver operating characteristic （ROC） curve was used to evaluate the predictive value of each risk factor. Results Compared with the non-severe neurological function impairment group，the severe neurological function impairment group had a significantly lower level of HDL-C and significantly higher levels of non-HDL-C，PIV，IL-1β，IL-6，and IL-8 （P<0.05）. The multivariate logistic regression analysis showed that HDL-C，non-HDL-C，PIV，IL-1β，IL-6，and IL-8 were influencing factors for severe neurological function impairment in elderly patients with acute ischemic stroke （P<0.05）. The ROC curve analysis showed that the combination of HDL-C，non-HDL-C，PIV，IL-1β，IL-6，and IL-8 had a significantly higher efficiency than each indicator alone in predicting severe neurological function impairment in elderly patients with acute ischemic stroke （Z=4.234，4.411，3.897，4.240，4.001，4.420，all P<0.001）. Conclusion Elderly patients with acute ischemic stroke who have relatively high levels of PIV，non-HDL-C，and pro-inflammatory ILs tend to have severe neurological function impairment.