This study explores whether children's social competence can be promoted in elementary school. An intervention program, emphasizing discussion among students around conflicting opinions in social interactions, was conducted within the Icelandic educational system for one academic year. Reflecting the study's balanced design, 96 children (48 girls and 48 boys) aged 8 (48 children) and 11 (48 children), were selected at random from eight classes to participate. Teachers in four of the classes received special training in working with their students on social conflict resolutions, whereas the other four teachers did not receive such training. The children were interviewed twice, in the beginning and again at the end of the academic year, on "everyday" school-based dilemmas in which a student communicates with either a teacher or classmate over conflicting opinions. In addition, both observations and teacher ratings were used to explore children's "real-life" social interactions with their teachers and classmates. For each situation, children's thought processes and actions were classified independently at one of four developmental levels of perspective coordination (impulsive, unilateral, reciprocal, mutual). Actions were also classified according to interper¬sonal orientation or style (self-transforming, other-transforming). Results indicate that children who participated in the intervention program improve more in thought level, expressing a greater progress in reciprocity, than children in the regular program. Moreover, in real-life situations, children in the intervention program improve more in action level when negotiating with classmates, showing more increased reciprocity in their social conflict resolutions, than children who do not receive any special training. This difference between groups in action level was, however, not detected in situations with teachers. Finally, across teacher and classmate real-life situations, children in the intervention program became less assertive over time than children in the regular program.