To assess whether the use of complementary and alternative medicines therapies (CAMs) for prostate cancer and/or its treatment side effects by long-term survivors is associated with selected socio-demographic, clinical, health-related quality-of-life (HRQOL) and/or psychological factors.The Prostate Cancer Care and Outcomes Study (PCOS) is a population-based cohort study of men with prostate cancer who were aged less than 70 years at diagnosis in New South Wales, Australia. Included in these analyses were men who returned a 10-year follow-up questionnaire, which included questions about CAM use.Validated instruments assessed patient's HRQOL and psychological well-being. Poisson regression with robust variance estimation was used to estimate the adjusted relative risks of current CAM use for prostate cancer according to socio-demographic, clinical, HRQOL and psychological factors.996 of 1634 (61%) living PCOS participants completed the 10-year questionnaire. Of these 996 men, 168 (17%) were using CAMs for prostate cancer and 525 (53%) were using CAMs for any reason (including prostate cancer). Those using CAM for prostate cancer were more likely to be regular or occasional support group participants (vs. no participation RR = 2.02; 95%CI 1.41-2.88), born in another country (vs. Australian born RR = 1.59; 95%CI 1.17-2.16), have received androgen deprivation treatment (ADT) since diagnosis (RR = 1.60; 95%CI 1.12-2.28) or in the past two years (RR = 2.34; 95%CI 1.56-3.52). CAM use was associated with greater fear of recurrence (RR = 1.29; 95%CI 1.12-1.48), cancer-specific distress (RR = 1.15; 95%CI 1.01-1.30), cancer-specific hyperarousal (RR = 1.17; 95%CI 1.04-1.31), cancer locus of control (RR = 1.16; 95%CI 1.01-1.34) and less satisfaction with medical treatments (RR = 0.86; 95%CI 0.76-0.97), but not with intrusive thinking, cognitive avoidance, depression, anxiety or any HRQOL domains.In this study, about one in six long term prostate cancer survivors used CAMs for their prostate cancer with use centred around ADT, country of birth, distress, cancer control, fear of recurrence and active help seeking.