In the present study we examined the relevance of selected personality variables, namely Eysenck's factors of extraversion, psychoticism and neuroticism, and the psychological well being factor of self-esteem to the tendency to bully and to be victimized. Male primary school children (n = 87) with a mean age of 10.9 years completed the Junior Eysenck Personality Inventory and the Coopersmith Self Esteem Inventory. Children's tendency to bully and to be victimized was assessed by means of questionnaire and teacher nomination. As predicted the tendency to bully was found to be significantly associated with psychoticism while the tendency to be victimized was significantly associated with introversion and low self-esteem. The expected association between being victimized and neuroticism was not confirmed.