Since problem solving skills play a central role in middle and secondary school mathematics curricula, this made mathematics educators give importance to this subject. Improving problem solving skills of students is one of the primary aims of education so it is very important to make students gain problem solving skills. Thus, the aim of this research is to investigate views of middle and secondary school mathematics teachers related to improvement of students' problem solving skills. Qualitative research method was used in this study. The research was done on fall term of 2015-2016 academic year. The study was conducted with 115 mathematics teachers (60 middle school and 55 secondary school) working at state schools. Data were gathered by a form consisted of open ended questions and analyzed by descriptive and content analysis techniques. At the end of the research, it is found that teachers had information about the importance of problem solving skills improvement in mathematics education. Also, it is determined that participants thought teachers should have a central role in improving problem solving skills and students should strive in problem solutions. In addition, it was found that teachers believed that mathematics and other lessons improved problem solving skills and improvement in problem solving skills had a positive effect on the achievement in mathematics and other lessons. Lastly, teachers thought that students whose problem solving skills had improved were more successful than the other students and had higher self-confidence than others. They also stated that since it had an impact on improvement in problem solving skills, it should be given importance to level of students when the textbooks were prepared. [This paper was presented at the International Conference on Education in Mathematics, Science & Technology (ICEMST) (2016).]