Background: Cancer patients’ potential for severe financial toxicity (FT) is well-established, however there is limited data on the magnitude of this challenge associated with treatment of localized prostate cancer (PC). The extent to which men consider potential financial implications prior to selection of a treatment strategy remains poorly understood. Methods: Between 5/2020-10/2020, 1233 insured PC patients treated at a comprehensive cancer center completed a one-time FT survey which included the COmprehensive Score for financial Toxicity (COST) instrument, impressions of PC costs and financial coping strategies. Inclusion criteria was localized disease and treatment with either radical prostatectomy (RP) or definitive radiotherapy (RT) in the previous 4-26 months (mo) or at least 6mo of active surveillance (AS) prior to survey. To assess possible temporal differences in FT, responses were grouped into 6, 12, 18 and 24 months after treatment start, and we plotted COST against time, using generalized additive models to allow for non-linearity. Results: Overall, 988 men were eligible for analysis: 347 (35%) underwent RP, 384 (39%) underwent RT, and 257 (26%) were on AS. The median age at survey completion was 67 years (quartiles 62, 72). Men were predominantly white (89%), English-speakers (99%) and married (84%). The median (quartiles) COST score for all patients was 33 (26, 38) with possible range of 0-44 with lower scores indicating greater FT; median values were identical with similar quartiles (+/- 1 point) when stratified by treatment type. There were no significant changes in median COST between men surveyed at the four time points for any treatment subgroup. In total, 66 men (7.1%) reported spending > 20% of annual income on treatment and 10% felt that PC has created at least somewhat of a financial hardship for their family. Top drivers of burdensome cost included medical bills (37%) and transportation costs (21%). Most (83%) reported giving little or no consideration to possible costs prior to making a PC treatment decision, yet the majority (77%) felt that out of pocket costs should be communicated to a patient prior to decision making. Most believed patients should definitely (46%) or possibly (33%) have the opportunity to discuss financial concerns with the radiation oncologist or urologist. Conclusions: Our study is the first reported use of the COST instrument to assess subjective financial distress in localized PC patients. Our results demonstrate that the overall degree of FT in this cohort of insured patients treated at a specialized cancer center is low. While potential financial burden does not strongly influence treatment decision making in this cohort, most want this information and an opportunity to discuss financial concerns with their oncologist. Next steps include identification of predictors for high FT risk and extension of our survey to hospital systems with differing demographic profiles.