BACKGROUND Intracranial causes of dysosmia are uncommon. Nonetheless, a missed intracranial disorder or neoplasm is worrisome. Magnetic resonance imaging (MRI) may be used in diagnosis; however, the cost effectiveness of this practice is unclear. We hypothesize that MRI scans for idiopathic dysosmia will demonstrate sufficient significant findings to be a cost-effective screening tool. METHODS Tertiary-care otolaryngology clinic records were queried for smell and taste disturbance. The patients underwent anosmia-protocol MRI of the brain for idiopathic dysosmia in 122 cases. Each MRI report was reviewed for dysosmia findings, intracranial neoplasms, and incidental findings. RESULTS MRI was normal in 44.3%, there were dysosmia-related findings in 25.4%, and incidental findings in 40.2%. The most common related diagnosis was occult frontoethmoid sinusitis (18.8%). The most common incidental diagnosis was small vessel disease (21.1%). Intracranial neoplasms were observed in 6 patients (4.9%). Nine patients had intracranial causes of dysosmia including olfactory meningiomas, infarct, trauma, and atrophy. MRI cost per dysosmia etiology diagnosis was $9445. Costs increased to $32,355 and $48,880 per intracranial cause or neoplasm, respectively. Cost to diagnose 1 causal intracranial neoplasm was $146,400. From 1997 to 2003, median medical malpractice settlements ranged from $625,616 for misdiagnosis to $682,500 for delay in treatment to $1,750,000 for brain injury. The median jury award was $975,000 for misdiagnosis, $1,550,000 for delayed treatment, and $6,000,000 for brain injury. CONCLUSION MRI in idiopathic dysosmia yielded information regarding the diagnosis in one-quarter of cases. The implications of missing an intracranial neoplasm alone justify the cost of screening MRI for idiopathic dysosmia.