The aim is to establish the role of head computed tomography (CT) and magnetic resonance imaging (MRI) in adults presenting to the emergency department (ED) with first-time seizure (FS) and to analyze the potential predictor variables for the adverse imaging outcome. We retrospectively reviewed the medical records of all adults who underwent cranial CT or MRI between January 1, 2011, and December 1, 2016, to an academic ED for FS. Patients were excluded if were under 18 years of age, had known recent intracranial pathology, known brain tumor or having a history of trauma. Important predictive variables to indicate pathology in either CT or MR scan in patients with FS were evaluated with logistic regression analysis. A total of 546 FS (293 men and 253 women; range, 18-81 years; mean, 47 years) were identified in patients receiving either cranial CT or MR scan. Of them, abnormal findings were observed in 22/451 (4.8%) patients on CT and 18/95 (18.9%) patients on MRI. Predictor variables of age greater than 50 years, focal neurologic deficit, hypoglycemia, and history of malignancy were identified on CT, whereas a history of malignancy, age greater than 50 years and focal neurological deficit were determined on MRI. Limiting neuroimaging to this population would potentially reduce head CT scans by 67% and would potentially reduce head MRI scans by 47%. Clinical suspicion should be heightened and the neuroimaging should be considered for advanced age, history of malignancy, hypoglycemia or focal neurological deficits in patients with FS.