The purpose of this research was to investigate the effects of the computer-assisted and computer-based instructional methods on students achievement at computer classes and on their attitudes towards using computers. The study, which was completed in 6 weeks, were carried out with 94 sophomores studying in formal education program of Primary Teaching Department of Education Faculty at Trakya University. The participants were distributed into experimental and control groups by pre-test post-test control group design. A computer attitude scale, a level-designation test and a practice test were used to collect the data. To evaluate the data, t test was used in the program of SPSS 12.00. According to the study results, the students receiving computer-assisted instruction during their computer classes showed higher success on the practice test than the students taking classes with computer-based instructional methods. Additionally, a considerable difference has not been seen in the attitude of the students towards using computers from the other standpoints of the study.