The purpose of this study is to determine levels of science process skills of pre-service classroom teachers and to examine relationships between their science process skills and science achievement. The study had a descriptive survey design. Data were collected through “Personal Information Form” and “Science Process Skills Test” (SPST) which was developed by Aydoğdu (2006). The SPST consists of nine multiple–choice items with a reliability coefficient of .70, which requires reasoning for responses and seven scenarios. The SPST was administered to 143 pre-service classroom teachers in a public university and data were analyzed by t test, Pearson product-moment correlations, and one way analysis of variance (ANOVA). Results indicated that science process skills of students differed on their grade level, but not on gender. Besides, moderate positive correlation (r=.38) was found between science process skills and science achievement.