This study was carried out to find out the effect of dietary intake on cognitive function retardation in old age using dietary survey and cognitive function test. The subjects were 332 men of 50-94 years old and their activities of daily living were very similar. The cognitive function was tested by Mini Mental State Examination (MMSE)-K which was translated from MMSE, and the 24-hour recall method was used for dietary survey. Scoring of MMSE-K was a little different from MMSE, that is, in case of no education, one to four points were added to exclude the effect of education which has been considered as a confounder by many researchers. The number of subjects belonging to below 23 of MMSE-K score was increased by increasing age. Even though points were added in case of no education, the ratio of below 23 MMSE-K score group was diminished by increasing education. Therefore, education seems not to be a confounder but a independent variable on cognitive function. Income, past occupation, family type, self-evaluated health status did not play any effect on cognitive function significantly. On the other hand, the correlation between each nutrients and the score of cognitive function test showed that the more consumption of vitamin A and protein, the higher cognitive function score was obtained. In case of iron and Ca, even though it was not statistically significant, there was a tendency of increasing cognitive function score by increasing the intake of those nutrients. This study suggests that micronutrient intakes might be more related to cognitive function than macronutrients.