We reconstructed in three dimensions, and measured by a computer-aided method developed by us, Scarpa's ganglion and surrounding important anatomical structures in 7 normal human temporal bones obtained from 7 individuals aged 7 days to 72 years. We found that this ganglion is shaped like an hourglass and lies with its superior part directed anterosuperolaterally, and its inferior part posteroinferomedially; these two parts are connected by the isthmus ganglionaris. Although the dimensions of the parts of the ganglion varied, such a structure was distinguishable in all the specimens we studied. The volume of the ganglion was found to be relatively consistent in these postnatal specimens; although the width and height of the ganglion varied, they were inversely correlated with each other (linear regression analysis, p < 0.05). We did note, however, some postnatal increase in the distance from the ganglion to its neighboring structures. We also identified a significant correlation between the width of the ganglion and the length of the internal auditory canal and the distance from the ganglion to the vestibular endorgans in any given specimen (linear regression analysis, p < 0.05). These results suggest that although the volume of Scarpa's ganglion does not change after birth, its shape does change with the growth of the individual temporal bone.