Purpose: The purpose of this study was to find out primary school students' basic process skills (BPSs) in terms of select variables. In addition, this study aims to investigate the relationship between BPSs and academic achievement. Research Methods: The study had a survey design and was conducted with 1272 primary school students. The study data were obtained from the "Test of Basic Process Skills-- BAPS." BAPS was originally developed by Padilla, Cronin and Twiest (1985) and adapted to Turkish by Aydogdu and Karakus (2015). Findings: The results indicated that the BAPS scores of primary school students are not at a satisfactory level. Moreover, results indicated that the BAPS scores of primary school students were higher among the upper grades than the lower grade levels. Other results indicated that the BAPS scores of primary school students were higher among students coming from better socio-economic levels than those with low level socio-economic backgrounds. Furthermore, the BAPS scores of primary school students were higher among primary school students in urban areas than those living in rural areas. Finally, the results indicated that a positively significant relationship was found between primary school students' basic process skills and achievement in science courses. Implications for Research and Practice: Teachers have the great responsibility to develop the BPSs of students. The socio-economic levels of students must be taken into account during in-class activities that are the focus of BPSs. The results suggest that the more BPSs primary school students acquire, the more academically successful they will be.