Objective To investigate the associated factors and trends of prehospital delay in elderly patients with acute ischemic stroke (AIS).Methods Elderly patients with AIS admitted to the First People's Hospital of Qujing from 2007 to 2017 were enrolled retrospectively.The data of patients was collected from the medical records.Onset-to-door time ＞ 2 h was defined as prehospital delay.The demographic and baseline data were compared between the delay group and the non-delay group.Multivariate logistic regression analysis was used to determine the associated factors for prehospital delay.In addition,the trends of prehospital delay time at the different stages of the study were also analyzed.Results A total of 1 566 patients with AIS aged ≥65 years were enrolled.Their mean age was 75.61 ±6.06 years.The mean time of prehospital delay was 10.83 ± 7.47 h (median time 8.27 h).Multivariatelogistic regression analysis showed that advanced age (odds ratio [OR] 1.271,95％ confidence interval [CI] 1.029-2.896;P =0.039),nocturnal onset (OR 1.413,95％ CI 1.067-3.859;P=0.013),and atypical symptom onset (OR 2.345,95％ CI 1.184-8.126;P=0.029) were independently positively correlated with prehospital delay,while the emergency medical service transport (OR 0.743,95％ CI 0.261-0.998;P =0.010),having medical insurance (OR 0.219,95％ CI 0.015-0.799;P =0.042),and having a bystander at the time of onset (OR 0.618,95％ CI 0.149-0.814;P=0.003) were independently negatively correlated with prehospital delay.At the different stages of the study,January 2007 to October 2010,November 2010 to April 2015,and May 2015 to December 2017,the mean time of prehospital delay was 12.59 ± 7.06 h,10.57 ±7.78 h,and 8.47 ±7.07 h,respectively.They showed a decrease trend,but the difference was not statistically significant.Conclusion Advanced age,nocturnal onset,and atypical symptom onset were the independent risk factors for prehospital delay,while emergency medical service transport,having medical insurance,and having a bystander at the time of onset were the independent protective factors for prehospital delay.The delay time of the elderly patients with AIS is declining year by year,but the improvement is not significant.The delay in seeking timely medical intervention remains an important public health problem.