The purpose of this research was to examine the correlation of two personal factors with aggressiveness. The first was self-image and its aspect: self-esteem. No significant correlations were presumed between aggressiveness and self-image or between aggressiveness and self-esteem, because previous research gave inconsistent results. More recent research has shown that there may be other aspects of self-esteem that are more relevant for its relation to aggressiveness, i.e. fragility of high self-esteem (Baumeister, Smart, & Boden, 1996; Kernis, 2003; Kernis, Grannemann, & Barclay, 1989). Therefore significant correlations between aggressiveness and fragile high self-esteem were presumed. The second personal factor, which might correlate with aggressiveness, was optimism. Existing data report of negative connection between optimism and aggressiveness, which was also presumed in this research. These presumptions were examined on a sample of more than 50 women, aged 19 to 34, who were college students or had a college degree. The Aggression Questionnaire (Buss and Perry, 1992) was used to measure aggressiveness, Adult Sources of Self-Esteem Inventory was used to measure self-image and Rosenberg Self-Esteem Scale was used to measure the level of self-esteem. The fragility of self-esteem was measured in three ways: with the measurement of false responses about the level of self-esteem, contingent self-esteem and instability of self-esteem. The Generalized Expectancy for Success Scale - revised and Life Orientation Test - revised were used to measure optimism. The results showed that only hostility, as a form of aggression, was related to self-image and the level of self-esteem. Other forms of aggression were not significantly related to self-image and the level of self-esteem. Fragile high self-esteem was related to summary aggression and some specific forms of aggression, especially hostility. Optimism was correlated with hostility and physical aggression, but not with other forms of aggression.