The aim of this study was to assess the frequency and imaging characteristics of focal levator eventrations in patients with pelvic floor dysfunction on magnetic resonance (MRI). A review of 81 dynamic MR pelvic examinations in patients with pelvic floor dysfunction was carried out to detect and characterize focal eventrations in the levator ani muscle. These were defined as muscle outpouchings which made an angle of >180 degrees with the remainder of the muscle and had a depth of >or=1 cm. Of 81 patients 11(13.5%) had focal eventrations in the levator muscle on MRI: bilateral in 2 cases, right in 5 and left in 4. There was protrusion of pelvic viscera into the eventration in 5 cases, fat in 7 and fluid in 1. Focal levator ani muscle abnormalities are not uncommon on MRI in patients with pelvic floor dysfunction. Characterization of levator muscle morphology can be useful as a research tool in this population.