In this research, the effects of teaching of the cooperative problem-solving strategies on the students’ of physics achievement and achievement motivation were investigated. Experimental procedures were carried out on high school students at fall semester of 2005-2006 academic year in Izmir. In this study, the pre and post test research model with control group was used. The research was performed on two groups. Research data were collected through Physics Achievement Test, The Surveys of Problem-Solving Strategies and Achievement Motivation. During this study, problem-solving strategies were applied to the experimental group by the cooperative learning method while they were applied to the control group by conventional teaching. In conclusion, the averages of experimental group’s physics achievement and achievement motivation were found to be significantly higher than those of the control group’s.