It has been proposed that aging selectively affects cognitive processes that are effortful rather than automatic and that active, memory-driven attentional selectivity is impaired in old adults. The present study evaluated attentional selectivity in two groups of healthy adults: a younger group with mean age 19.4 years and an older group with mean age 63.6 years. A visual simple reaction time task was used in which a warning cue appearing at the beginning of each trial indicated the probable location of the target signal. Response times of both groups were shortest when the stimulus appeared at the expected location and longest when it appeared at the unexpected location; responses of both groups were also faster on trials with a 3-s warning interval compared with a 2-s warning interval. These effects of spatial and temporal expectancy were as substantial in older adults as in younger adults. Reasons for the difference between these findings and earlier results are discussed.