PurposeTo analyze the cost-effectiveness of performing a renal mass biopsy in advance of ablation or concurrent with a percutaneous ablation procedure for the management of small renal masses (SRMs). MethodsA decision-analytic model was developed with a cohort of 65-year-old male patients with an incidental, unilateral 1 to 3 cm SRM. A decision tree modeled the first year of clinical intervention, following which patients entered a Markov Model with a lifetime horizon. Patients were assumed to be treated in accordance to established clinical practice guidelines, including surveillance, repeat ablation for recurrence, and systemic therapy for metastasis. Healthcare cost and utility values were determined from published literature or local hospital estimates, discounted at 1.5%. Total lifetime costs were calculated from the perspective of a Canadian health-care payer and converted to 2022 Canadian dollars. The primary outcome was incremental cost effectiveness ratio (ICER), at a willingness-to-pay threshold of $50,000 per quality-adjusted life-years gained. The secondary outcome was ICER at a willingness-to-pay threshold of 50,000 $/LY gained. ResultsConcurrent biopsy and ablation resulted in a gain of 16.4 quality-adjusted days, at an incremental cost of $386, with an ICER of 8494 $/QALY. The concurrent strategy was the dominant for prevalence of benign mass below 5%. Sequential biopsy and ablation was only cost effective when life-years were not quality-adjusted, and ablation cost was greater than $4300 or benign mass prevalence was greater than 28%. ConclusionConcurrent biopsy and ablation is cost-effective relative to pre-treatment diagnostic biopsy for management of incidental small renal masses.