Functional magnetic resonance imaging (fMRI) research in obsessive-compulsive disorder (OCD) has explored a broad range of cognitive functions, in addition to the neural correlates of symptom provocation and symptom improvement after treatment. There are some discrepancies between findings of symptom provocation fMRI research, which might be caused by the heterogeneous character of OCD, such as the variety of the symptoms and comorbidity, or the diversity of applied cognitive paradigms in neuroimaging research. Future research on symptom-specific neural correlates and related cognitive dysfunctions will bring better understanding to the pathophysiology of OCD. In addition, genetic or family studies will give information regarding traits or state-related characteristics as well as putative vulnerabilities to the disorder. Finally, considering the current model of cortico basal ganglia-thalamo-cortical loop dysfunction of OCD, functional connectivity research that examines the functional relationships between these brain areas will facilitate the understanding of the disorder.