Functional magnetic resonance imaging (fMRI) was used to compare cortical nociceptive responses to painful contact heat in healthy young (ages 22-30, n = 7) and older (ages 56-75, n = 7) subjects. Compared to young subjects, older subjects had significantly smaller pain-related fMRI responses in anterior insula (aINS) (P < 0.04), primary somatosensory cortex (S1) (P = 0.03), and supplementary motor area (P = 0.02). Gray matter volumes in S1 and aINS were significantly smaller for the older group (P = 0.02 and 0.0001, respectively), suggesting reduced processing capacity in these regions that might account for smaller pain-related fMRI responses.