The association of Alzheimer Disease (AD) with reduced fertility and increased parental age at time of birth were investigated in a sample of 126 individuals with AD. Relative to their normal siblings, maternal age at time of birth of the ADs was not significantly increased, nor were the AD individuals more likely to be later-borns in their sibships. The percentage of individuals bearing children was 75.7% for AD versus 70.8% for their normal siblings. For those ever bearing children, ADs produced slightly more children than their normal siblings (average of 3.92 versus 3.67). It was concluded that AD is not associated with either reduced fertility or increased parental age.