We examined the joint factor structure of self-reports and observer reports on the facet scales of the HEXACO Personality Inventory—Revised in a sample of 563 pairs of well-acquainted persons. In separate analyses based on a targeted orthogonal rotation and on a CFA model, we identified six trait factors (representing the HEXACO dimensions) plus two source factors (representing the favourability bias of self-reports and observer reports, respectively). All six trait factors were recovered with substantial loadings for the appropriate facet scales. The content of the self-report and observer report source factors suggested that the former mainly involved ‘egoistic’ or ‘agentic’ biases and the latter mainly involved ‘moralistic’ or ‘communal’ biases. Copyright © 2010 John Wiley & Sons, Ltd.