Acute urinary retention is a urologic emergency that can affect elderly men. It requires prompt bladder decompression and identification of the underlying cause. Elderly patients with acute urinary retention often have associated fecal impaction, delirium, and constitutional symptoms. With increasing age, hospitalization for acute urinary retention may be necessary to treat precipitating events, whereas acute urinary retention itself might precipitate or exacerbate comorbid medical conditions, necessitating hospitalization. Multiple causative factors operate via 3 main mechanisms: obstructive, neurogenic, and detrusor underactivity. More than 1 mechanism might exist in a single patient. Definitive treatment must be individualized on the basis of the quality of life, life expectancy, caregiver support, and presence of other chronic medical conditions. Urology consultation may be needed for invasive diagnostic testing or management of refractory cases.