This study investigated the correlation between interleukin (IL)-1β-511C/T gene polymorphism and myocardial infarction (MI) complicated with ischemic stroke (IS). A total of 251 MI patients complicated with IS (observation group) and 200 healthy people (control group) were selected for the case-control study. IL-1β-511C/T gene polymorphism was detected via polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The genotype distribution and allele frequency were compared between the two groups, and the correlation between gene polymorphism and MI complicated with IS, was analyzed after traditional risk factors were adjusted by using logistic regression method. The frequencies of CT and TT genotypes in the observation group were higher than those in the control group (P<0.05). The frequency of T allele in the observation group was significantly higher than that in the control group (P<0.05), but the frequency of C allele was obviously lower than that in the control group (P<0.05). According to results of logistic regression analysis, arrhythmia and high-density lipoprotein cholesterol (HDL-C) were associated with MI complicated with IS. In patients with arrhythmia, the risk of disease in carriers with IL-1β-511T gene was 1.7-1.8 times that in non-carriers [odds ratio (OR) = 1.742 and 1.839, P<0.05]. In patients with abnormal HDL-C, the risk of disease in carriers with IL-1β-511T gene was 2.0-2.2 times that in non-carriers (OR = 2.011 and 2.249, P<0.05). Besides, the risk of MI complicated with IS in carriers with CC genotype had no significant difference in patients with arrhythmia and abnormal HDL-C (P>0.05). IL-1β-511C/T gene polymorphism may be related to the risk of MI complicated with IS.