Anecdotal evidence suggests that the foramina of the cribriform plate which transmit cranial nerve I decrease in size with age, but this finding has never been supported with quantitative data. It has also been observed that olfactory function declines with increasing age. It has been hypothesized that the cribriform plate foramina closure may be responsible for the olfactory performance decrease with age. We gathered quantitative data to test an age-related decline in cribriform plate foramina area. We report data for the area of patent foramina in the posterior 1 cm of 57 cribriform plates from 40 skulls of known age and sex. Analyses were performed to test for the effects of age, sex, and lateralization on foramina area. The area of patent foramina in the cribriform plate decreases with increasing age. Age is a strong covariate with foramina area (P value = 0.0025). The regression equation for the area of patent foramina is: expected area = 8.17 - (0.06) age. Adding the variable sex does not contribute significantly (P value > 0.28) to the model which utilizes age alone. Nor was there any significant lateralization in patent foramina area. The area of patent foramina in the cribriform plate decreases with increasing age, and there is no significant difference between males and females or left and right sides. Such decreases in patent foramina may be associated with impaired olfactory function in the aged.