<b><i>Background:</i></b> An international workshop on cancer predisposition cascade genetic screening for hereditary breast and ovarian cancer (HBOC) and Lynch syndrome (LS) took place in Switzerland, with leading researchers and clinicians in cascade screening and hereditary cancer from different disciplines. The purpose of the workshop was to enhance the implementation of cascade genetic screening in Switzerland. Participants discussed the challenges and opportunities associated with cascade screening for HBOC and LS in Switzerland (CASCADE study); family implications and the need for family-based interventions; the need to evaluate the cost-effectiveness of cascade genetic screening; and interprofessional collaboration needed to lead this initiative. <b><i>Methods:</i></b> The workshop aims were achieved through exchange of data and experiences from successful cascade screening programs in the Netherlands, Australia, and the state of Ohio, USA; Swiss-based studies and scientific experience that support cancer cascade screening in Switzerland; programs of research in psychosocial oncology and family-based studies; data from previous cost-effectiveness analyses of cascade genetic screening in the Netherlands and in Australia; and organizational experience from a large interprofessional collaborative. Scientific presentations were recorded and discussions were synthesized to present the workshop findings. <b><i>Results:</i></b> The key elements of successful implementation of cascade genetic screening are a supportive network of stakeholders and connection to complementary initiatives; sample size and recruitment of relatives; centralized organization of services; data-based cost-effectiveness analyses; transparent organization of the initiative; and continuous funding. <b><i>Conclusions:</i></b> This paper describes the processes and key findings of an international workshop on cancer predisposition cascade screening, which will guide the CASCADE study in Switzerland.