To determine the presence and nature of variability in anxiety and depression in patients with prostate cancer (PCa) over 3 years following diagnosis, 442 patients with PCa completed standardized anxiety and depression inventories via survey between 1 and 36 months after receiving their initial diagnosis. Data were analyzed from a series of 3-month cohorts, and results indicated that total scores and incidence of clinically significant anxiety and depression varied over time, but that this variability was restricted to specific subfactors of anxiety and depression. Provision of effective psychological treatment to patients with PCa is discussed.