The target of this study was to examine the impact of meta-cognitive thinking on problem-solving in grade (11) in the south of Al Batinah governorate in the Sultanate of Oman. The researcher depends on the correlative descriptive approach to discover the relation between student’s variables (changes). There were (532) students as a sample of this study. They were selected randomly by using a cluster randomization method. There were (8) schools, (4) were girl’s schools and (4) were boys' schools. The researcher applied two measures to verify the study hypotheses. The first measure was thinking skills and the second measure was problem-solving skills. The study has found a positive relation between meta-cognitive thinking and problem-solving. Metacognitive thinking assists in explaining (36%) of dissimilarity in problem-solving with a medium effect size. Moreover, it has been reached that grade (11) students in the south of Batinah have medium levels in all metacognitive thinking. In addition, students have got a medium level in the diminution of problem-solving changes. According to the research's results, she found no statistically significant difference in Meta cognitive. In general, it is attributed to the gender variable. Overall, there were differences in the planning dimension in Favor of males and the monitoring and organizing dimension due to the benefit of females. Moreover, there were statistically significant differences in metacognitive thinking attributed to the academic variable only. There were differences in the perception dimension due to the gender variable in favor of females. While there were statistically significant for the academic variable’s path in favor of the advanced path. Accordant to the researcher’s results which were achieved in this study, the researcher put several recommendations to highlight the concern for developing metacognitive thinking students for the important role it plays in raising the level of problem-solving among students. Keywords: Metacognitive thinking, problem–solving, grade (11) students.