Animal studies indicate that stress negatively impacts hippocampal structure; little is known, however, regarding the relationship between stress and hippocampal morphology in healthy humans. Twenty-one healthy adults underwent structural magnetic resonance imaging examinations and completed the Derogatis Stress Profile. Greater psychological stress at the time of the scan correlated significantly and more strongly with anterior than posterior hippocampal volume. These findings suggest that psychological stress may be associated with structural alterations in the anterior hippocampal formation and that this relationship may differ along the rostrocaudal axis of the hippocampus. Our results may also have implications for neuropsychiatric disorders that have implicated stress and hippocampal abnormalities in their pathogenesis.