A method for determining the ages of active red-cockaded woodpecker (RCW) (Picoides borealis) cavities was developed based on data from 22 RCW cavity trees downed in the Francis Marion National Forest by Hurricane Hugo. Cavity age was measured in growing seasons of the tree from the date of cavity initiation. Age determination was based macroscopic and microscopic wound responses in wood removed from the side of the cavity entrances. The method was tested on 8 active cavities of known age located in the Sandhills Gamelands, North Carolina. All of the cavity age estimates were within 2 years of the known ages. In the year following the test no adverse effects on the birds have been reported. A method for rougher estimation of cavity ages is also presented as are suggestions for improvement, further testing, and application of both cavity aging methods.