We report a case of Crohn's disease in a patient with relapsing-remitting Multiple Sclerosis diagnosed and in treatment at Walter Cantidio Hospital -- UFC -- Fortaleza, state of Ceara, Brazil. N.N.O.A., female, 44 years old, no smoker, started in 1994 sensitive alteration in the legs with sensitive level until T4. She was submitted to investigation and was diagnosed with multiple sclerosis. After 6 years started treatment with immunomodulators, however she had 6 outbreaks and collateral effects, so in 2012 changed treatment to natalizumab, and her EDSS decreased from 2 to zero after 6 pulses. The Crohn's disease was diagnosed in 2002 by biopsy, and started with proctitis, diarrhea and fecal incontinence. Actually, she treats the Crohn's disease with mesalazine. In September of 2008 she had a relapse of the Crohn's disease in concurrence with an outbreak of the multiple sclerosis (MS), and was submitted to pulse with methylprednisolone, improving both diseases. Although MS and inflammatory bowel disease (IBL) may share common predisposing factors, not enough information is available to speculate about possible mechanisms. Concurrence of the 2 diseases is greater than expected, so cases like this may be reported to trace an adequate therapeutic. [ABSTRACT FROM AUTHOR] more...