Introduction: Over the recent years, the sources of stress and unfavorable situations are increasingly rising. The previous studies indicate that resiliency and optimism are supportive factors which leading to adaptation to adverse conditions and consequently well-being. The purpose of this study was to predict psychological well-being through resiliency and optimism.Method: 414 students of medicine (213 boys and 191girls) were selected at average age of 21-24 and standard deviation of 2.2, using multistage cluster sampling. They were required to complete the questionnaires of Ryff Scales (RSPWB), Connor-Davidsons (CDRISC) and Optimism Scales of Carver and Scheier (Life Orientation Test, LOT).Results: The findings indicated that resiliency can predict psychological well-being by 27 percent. There was no significant difference in variables between the two genders.Conclusion: The Results showed that psychological well-being is influenced by personality factors such as resiliency. Regardless of the level of resiliency, optimism can relatively promote a feeling of well-being.