Psychosis in late lifeLate life psychosis can be seen in numerous psychiatric conditions, including schizophrenia (early and late onset), delusional disorder, depressive disorder, bipolar disorder, delirium, and major neurocognitive disorders (formerly dementia) of various etiologies. It can also present in systemic medical and neurological illnesses and can be related to the use of certain medications. Identifying the clinical features characteristic of specific disorders can assist in making an accurate diagnosis of psychosis in the geriatric population. Treatment will depend on the condition within which the psychosis presents. Judicious use of low-dose antipsychotics in older patients with psychosis is recommended and effective while monitoring for safety concerns and tolerability. Limited yet emerging research also suggests the use of psychosocial treatments for psychosis. This chapter provides an overview of the various psychiatric and systemic medical conditions associated with psychosis in the geriatric population, including an approach to diagnostic evaluation and evidence-based management. The chapter will conclude with two clinical case studies to highlight the complexities inherent in the clinical management of late-life psychosis.