In a twelve month period, ten patients with fistulas related to Crohn's disease were explored by magnetic resonance imaging performed with a high-field supraconductive magnet. This technique demonstrated 3 cases of peri-anal abcesse invisible by other imaging modalities, and in 8 cases, fistules tracts, including 5 complex fistules, and one communicating with the bladder. This examination defined the extension of these lesions relative to the elevator plane, and demonstrated diffusion to the inferior space in 4 cases, to the superior space in 2 cases, and to both spaces in 2 cases. This method seems to be efficacious and does not expose the patient to X-rays.