In our study, we have focused on the relationship between certain types of aggression and the sociometric status of primary school children, considering the effect of these factors on the hostile character of cognitions that aggressive children generate towards their peers. Sample: Our sample consisted of 321 primary school children from Transylvania (M=10.25 years, SD= 0.71), out of which 61.4% were of Romanian and 36.8% of Hungarian ethnicity. Method: our instruments measured the type of aggression, the sociometric status of children within the classroom, and the type of hostile cognitions towards peers. Results: gender differences and sociometric status has an effect on types of aggressive behavior. The results are useable in the field for prevention and intervention.