This study investigated the differences in peer preference, gender and temperamental characteristics of children aged five to six in relation to their social competence (SC) and behavioural adaptation. The data were collected through the use of 'Picture Sociometry Scale', 'SC and Behaviour Evaluation Scale' and 'Short Temperament Scale for Children'. The participants in the study were 42 preschoolers, their mothers and the children's teachers. The study was carried out in a preschool in Ankara, Turkey. The results revealed that children with higher peer preference showed more SC. Moreover, children with higher level of persistence and approach revealed increased SC while children with higher reactivity had greater anger-aggression behavioural orientation.