Embitterment is an emotional reaction to negative life events that are perceived to be unjust and unfair. However, the influence of experiencing diverse negative life events has not been empirically examined as a trigger of embitterment. In this study, we investigated whether embitterment is affected by the frequency with which individuals experience negative life events. A nationwide online survey of 2,024 adult South Koreans was conducted to collect data concerning embitterment, 16 types of negative life events experienced, and social demographics. The standardized Korean version of a self-rating scale for post-traumatic embitterment disorder (PTED) was used. The average of the individual self-ratings was subjected to multiple regression analysis. The level of embitterment varied according to the quantitative intensity of negative life events wherein experience of more negative events was associated with higher levels of embitterment. Respondents who did not own a house and had lower levels of income and education showed higher levels of embitterment. Political orientation almost reached the level of statistical significance in that Korean conservatives expressed a higher level of embitterment. Our findings substantiate the concept of embitterment as an emotional state to negative life events. Also, the existence of varying levels of embitterment manifestation can be explained by the association between frequencies of experiencing negative life events and the level of embitterment found in the present study.