Using computer in educational field has been classified into three groups: learning from computer, learning about computer, and learning with computer (Jonassen, 2000). It has been argued that there is an urgent need to use different teaching approaches (Al-sheikh, 1973; Bayrak&Bayram, 2010 Zaiton, 2004). Moreover, utilizing the benefits of instructional technology such as Computer-Assisted Instruction (CAI) has become a topic of interest within the educational field. Computer-assisted instruction and its facilities probably help students to understand the chemical concepts and develop their science processes skills. This study aimed to investigate the impact of computer-assisted instruction in chemistry course on development of science processes skills by ages ranged from (17-18) from secondary school in Saudi Arabia. The study was quantitative in nature and involved (61) students in science section. For data gathering, the experimental research was conducted. The research design was randomized pretest-posttest control group design, and the researchers created science processes measurement including two dimensions namely basic science processes skills (BSPS), and integrated science processes skills (ISPS) the dependent variable was students’ performance on the test of science processes skills. On the other hand, the independent variable was teaching method including two levels; traditional approach, and by using computer- assisted instruction in chemistry course. The findings revealed that the computer- assisted instruction in chemistry increases the students’ performance on the basic science processes skills (BSPS).