The purpose of this study was to investigate the effects of the computer-simulated experiment (CSE) and the problem-solving approach on students' chemistry achievement, science process skills, and attitudes toward chemistry at the high school level. For this purpose, two experimental groups were compared, with the control group using the conventional approach. The sample consisted of 200 ninth-grade students. The treatment for all groups was carried out over 9 weeks. Four instruments were used in the study: Chemistry Achievement Test, Science Process Skill Test, Chemistry Attitude Scale, and Logical Thinking Ability Test. The results indicated that the computer-simulated experiment approach and the problem-solving approach produced significantly greater achievement in chemistry and science process skills than the conventional approach did. The CSE approach produced significantly more positive attitudes toward chemistry than the other two methods, with the conventional approach being the least effective.