The purpose of this study is to investigate the predictor effect temperamental characteristics of Turkish children aged between 5 and 6 have on peer relationship variables (social impact, prosocial behaviour, aggression, asocial behaviour, exclusion, fear-anxiety, and victimisation). About 140 children, aged between 5 and 6, and their mothers, from Denizli in Turkey, participated in this study. The Short Temperament Scale for Children was used to measure the temperamental characteristics of children. The Child Behaviour Scale, the Victimisation Scale, and the sociometric technique based on peer nomination were used to assess peer relationship variables. Results of this study concluded that there was a significant positive relationship between the level of approach, persistence, and rhythmicity and social impact and prosocial behaviour; there was a significantly adverse relationship between the level of aggression, asocial behaviour, exclusion, fearanxiety, and victimisation. The children's level of inflexibility/reactivity had a significant inverse relationship with social impact and prosocial behaviour and a significant positive relationship with aggression, asocial behaviour, exclusion, fear-anxiety, and victimisation levels. All temperamental characteristics taken into consideration for this study had a significant predictor effect on peer relationship variables of children aged between 5 and 6.