The effect of surface defects on the electronic structure of CaVO3 has been studied by ultraviolet photoemission spectroscopy (UPS). We used flat surfaces obtained by in situ fracturing of single-crystalline samples in an ultrahigh vacuum, and rough surfaces obtained by scraping, which are presumed to contain many surface defects. It is shown that the UPS spectra of CaVO3 are very sensitive to the surface structures, which depend on the cleaning procedure. In addition, the oxygen-exposure dependence of the UPS spectra was investigated in order to evaluate the influence of those surface defects on the UPS spectra. We conclude that the UPS spectra observed on the CaVO3 surfaces (both fractured and scraped) are strongly influenced by the electronic structure characteristic of the surface.