Aceruloplasminemia (ACP) is a rare genetic disorder characterized by the triad of diabetes mellitus, retinal degeneration, and neurological symptoms. The patient’s clinical and biochemical features highlight substantial phenotype heterogeneity, contributing to the difficulties and delay in diagnosing ACP. We described a patient presenting with diabetes and abnormal iron studies due to ACP with typical neuroradiologic abnormality. A 56-year-old female patient visited our hospital with complaints of weight loss and anxiety. The leading cause of unintentional weight loss was uncontrolled diabetes. She was treated with oral hypoglycemic agents. Initial blood tests revealed unexplained microcytic anemia and high ferritin levels. We performed magnetic resonance imaging (MRI) of the brain to alleviate her excessive concerns about normal memory loss. We suspected that she might have ACP, based on the results of cortical pencil lining sign of the brain MRI and microcytic anemia with decreased ceruloplasmin (CP) and increased ferritin levels. Sequence analysis of the CP gene revealed homozygosity for c.2630 G>A, confirming the clinical diagnosis of ACP. The patient was started on deferasirox with progressive normalization of ferritin. In conclusion, unexplained anemia, often with microcytosis, diabetes, and typical neuroradiologic findings, is the best clue for early diagnosis of ACP.