This research was carried out to determine the impact of computer-assisted teaching on teaching English. The first phase of the research was designed as an experiment and computer-assisted teaching and traditional teaching methods were conducted synchronically in two different groups. In the second phase, effects of variables such as gender, age, receiving private lesson and types of high schools of the students who attended the implementation were analysed. The students of the first bachelor's level program were assigned to be the control group and the students of the second bachelor's level program were assigned to be the experimental group. The experimental group was given the computer-assisted lessons for twelve weeks but traditional teaching methods were meanwhile used in the classes of the control group. The experimental group used a compact disc in the laboratory as an educational material, which was prepared by the researcher. Data for attitude evaluation were gathered by questionnaires and success was evaluated through students' examination grades. In determining the success rate, pre-test and post-test grades were used as the data. At the end of the research, the results revealed that traditional teaching methods caused the students grouped according to the variables such as gender, age, private lessons and types of high schools to develop a negative attitude towards English lessons whereas computer-assisted teaching method led the students to develop a positive attitude. Although it was observed that traditional teaching methods made a positive impact on the success of the students in English classes, this impact was weaker than computer-assisted teaching did in the other group. The students who studied English in computer-assisted teaching classes showed a more positive attitude towards English classes than the ones who studied English using traditional teaching methods.