We conducted a case-control study to determine the prevalence of the CALHM1 P86L polymorphism (rs2986017) in patients with Alzheimer's disease (AD) in the Chinese population of mainland China, and also to clarify whether this polymorphism is a risk factor for AD. Fourteen heterozygous P86L carriers were identified among 198 AD patients. One control subject was also found to be a P86L heterozygous carrier. The allelic frequencies of the AD patients and control subjects were found to be significantly different. Our study indicates that the CALHM1-P86L polymorphism is associated with AD in the ethnic Chinese Han.