Purpose: The purpose of this study was (1) to compare the relationship between multiple choice test (MCT) and problem-based learning (PBL) achievement, and (2) to determine whether self-directed learning readiness (SDLR) factors influenced PBL achievement by SDLR levels in a hybrid PBL course. Methods: The subjects were 2nd year students (N=113) in a Hematology PBL course at Seoul National University, College of Medicine. For the study analysis, data were collected on PBL, MCT and SDLR scores. The SDLR instrument developed by West & Bentley consisted of 32 items and 6 factors. The SPSSwin？？ program was used to analyze the data and statistics including correlation, F-test, and multiple regression analysis. Results: Firstly, the results showed a significant relationship between PBL and SDLR scores (r=.583; p<.05). Meanwhile, the relationships between MCT and PBL (r=.145), and between MCT and SDLR scores (r=-.067) were insignificant. Secondly, the PBL score by SDLR levels (high, middle, low) showed a statistically significant difference (F=15.98; p<.05). Thirdly, it was proved by multiple regression analysis that the SDLR factors and PBL score by SDLR levels could be explained by the following three factors: love of learning (R2=18.8%; high level), self understanding (R2=17.2%; middle level), inquiry to learning (R2=19.0%; low level). Conclusion: The results of this study indicated that there was a significant correlation between PBL score and SDLR levels. It showed that the higher the SDLR scores, the more successful one is in independent situations such as PBL. Further study is needed so that suitable instructional methods for medical students can be conducted in an integrated curriculum.