Background: It is a major challenge to support training for simulated patients (SPs) and maintain a SP community. In order to promote the motivation of SPs, we conducted two sessions titled “clinical diagnostics lectures” . This study qualitatively explores the impact of the lectures for SPs.　Methods: Nine SPs who attended the clinical diagnostics lectures took part in focus group interviews. Transcripts were analyzed as per the Steps for Coding and Theorization (SCAT) method.　Results: Fifteen concepts and six categories were generated from the focus group interviews. The categories included <Medical information learning>, <Deepening understanding of scenarios>, <Effect on performance>, <Effect on feedback>, <Motivation for learning>, and <Concerns about biasing toward medical models>.　Discussion: “Clinical diagnostics lectures” provided to SPs offer a deeper understanding of scenarios and motivation for SPs to learn. However, there was concern about deviation from the patient’s perspective.