ObjectivesTo assess the potential number of European Union (EU) population(s), intervention, comparator(s), and outcomes (PICOs) based on European Network for Health Technology Assessment 21 (EUnetHTA 21) guidance and to explore further evidence-based opportunities to produce more predictable and workable EU PICOs. MethodsThe consolidated EU PICOs of 2 future hypothetical medicines in first-line non-small cell lung cancer (1L NSCLC) and third line multiple myeloma (3L MM) were derived using published health technology assessment reports of 2 recent medicines in similar indications based on EUnetHTA 21 proposed guidance. Sensitivity analysis assessed the impact of additional PICO requests. The number of analyses requested was estimated. ResultsIn 1L NSCLC and 3L MM, 6 and 9 EU Member States (MS), respectively, had published health technology assessment reports. PICO consolidation resulted in 10 PICOs for 1L NSCLC and 16 PICOs for 3L MM, increasing to 14 and 18 PICOs, respectively, when England’s National Institute for Health and Care Excellence scope was included to proxy remaining MS. A minimum of 280 and 720 analyses would be requested, exponentially increasing as additional outcome measures and subgroups are requested. ConclusionsThe PICO approach outlined by EUnetHTA 21 results in a significant number of analysis requests and substantial resources. Use of complementary analyses alongside evidence-based methods to derive PICOs and engaging with the health technology developer throughout the process would create a workable EU PICO that is predictable and most impactful for the EU, resulting in a timely and high-quality assessment report that is more usable at a MS level.