In this study we investigated popularity and perceived non-cooperativeness in multiethnic elementary schools. A sample of 94 pupils aged 10-12 years, from five multiethnic elementary schools, were divided into 26 teams and participated in a structured cooperative learning (SCL) curriculum of 11 lessons. Neither teachers nor pupils had prior SCL experience. The results show that SCL time increased popularity and decreased perceived non-cooperativeness across ethnic backgrounds. In addition, experience with SCL enhanced the popularity of immigrant pupils and decreased differences in perceived non-cooperativeness between immigrant and non-immigrant pupils. Importantly, SCL time only raised popularity and decreased perceived non-cooperativeness within ethnically heterogeneous teams. This last result extends the notion that enduring interethnic contact is fruitful for interethnic friendships. (Contains 1 table.)