The International Summer School on Pharmaceutical Analysis organized by the Division of Medicinal Chemistry of the Italian Chemical Society was held on 22-24.09.2021. The conference covered topics related to the most advanced analytical methods used in the development of new drugs and their production, among others. SSPA2021 focused on analytical methods for hit-to-lead performance and included the following main sessions: quality assurance in the hit-to-lead process, hit-to-lead: potency and selectivity, pre-ADMET studies, bioavailability and toxicology, analytical aspects in pre-formulation. The Summer School also included a special session on case reports discussed by R&D managers from drug discovery companies. Lectures were given by recognized experts from academia and industry.