CONTEXT: Crohn's disease presents very heterogeneous features from a clinical point of view, and classifying Crohn's disease patients in homogeneous subgroups in the light of genetic, molecular and clinical aspects is challenging. The Montreal Classification for Crohn's disease was proposed in 2005 as an effort to characterize Crohn's disease patients according to recent clinical and research advances in the field of inflammatory bowel disease. Since its proposition, the Montreal Classification needs an ample validation and application among different populations around the world. To date, there are no known studies applying the Montreal Classification to a Brazilian cohort of Crohn's disease patients. OBJECTIVES: To apply the Montreal Classification to a Brazilian cohort of Crohn's disease patients at a referral center for inflammatory bowel disease in Northwestern São Paulo State, Brazil. METHODS: We selected 90 consecutive well-characterized Crohn's disease patients assisted at Inflammatory Bowel Disease Outpatient Clinic between January 1992 and January 2007, with a minimum follow-up of 2 years; data concerning demographic characteristics, clinical onset of disease, age at diagnosis, time of disease, location and behavior of disease, presence of extraintestinal manifestations, familial occurrence, perianal involvement, treatment with biological drugs, and history of surgical treatment were evaluated. RESULTS: Male patients were predominant (54%), with a mean age at diagnosis of 33 ± 14 years old, and a median followup of 5.5 years. Most of the patients were diagnosed between 17 and 40 years old (59%), and had disease located in terminal ileum 46%), with a nonstricturing, nonpenetrating behavior (71%). Time of disease was correlated with necessity of biological treatment, disease behavior, and surgical treatment (P<0.05). CONCLUSIONS: These study findings are consistent with results from other studies conducted among different populations, although a further multicentric study with a larger number of patients would be necessary to validate the Montreal Classification among Brazilian population.