The purpose of this study was to investigate Turkish primary students’ scientific process skills under the theoretical framework of cognitive domain. The sample set consisted of 306 sixth and seventh grade students from public, private, and bussed schools. The Turkish Integrated Process Skill Test was used to measure scientific process skills, and the findings showed generally low scores. However, results indicated significant differences between sixth and seventh grade students at private and public schools. In addition, significant differences emerged among sixth grade students at each school type. Private school students had higher scores compared to public and bussed school students. Similarly, a significant difference was determined between sixth grade students at public and bussed schools. At the seventh grade level, private school students scored significantly higher than students at public and bussed schools. These differences are explained and discussed under the framework of cognitive domain and possible reasons for science achievement are identified.