Percutaneous nephrolithotomy (PCNL) is the standard treatment for patients with large stone burdens, but can be associated with significant complications. Flexible ureteroscopy is an alternative approach that is less invasive, but often requires multiple procedures. Typically, many factors play a role in the decision to perform PCNL or ureteroscopy. The challenge is that it is difficult to predict which stone burdens will be able to be cleared ureteroscopically. We describe our approach using initial prone ureteroscopy with the transition to standard prone PCNL if required.