Problem Statement: One of the main goals of education is to nurture individuals who know and improve themselves; who is well educated and have scientific perspective; who have developed communal coherency level; who are active, democratic and respectful to human rights. At the present time, according to an up to date mentality in mathematics education which is agreed on, the idea of learning mathematics by doing and experiencing rather than learning pure mathematical knowledge has come into prominence. In this process, there are many significant skills such as how to generate mathematical formulas, how to reach generalizations, how to reason will be developed Purpose of the Study: In this study the direct and indirect relationships between Mathematics success of vocational high school students and their attitudes towards the course, critical thinking tendencies and logical thinking skills were analyzed. Method: The research was conducted with 479 first grade students who study at various departments of Aydin Vocational High School at Adnan Menderes University. SPSS 19.0 and AMOS 16.0 packaged softwares were used for the analysis of the gathered data in the study. Findings: According to the test which analyses the direct relations among the variables, it was concluded that there was a positive and significant relation between students' critical thinking tendencies and Mathematics course success grades; positive, medium level significant relation between their attitudes towards Mathematics course and Mathematics course success; positive, medium level significant relation between students' critical thinking tendencies and their attitudes towards Mathematics course; positive, low level significant relation between their critical thinking tendencies and logical thinking skills. The results also showed that according to the test which analyses indirect effects among the variables, it was found that although the direct effect (0.014) of critical thinking on success was not statistically significant, the indirect effect (0.305) formed from the attitudes toward the course was significant. This result indicates that attitudes towards the course had an exact mediation role between critical thinking and Mathematics success. Moreover, the direct effect (0.793) of logical thinking upon success was statistically significant. Besides, indirect effect (0.031) formed from attitudes was also statistically significant. However, the intensity of this indirect effect decreased according to the first situation. This indicated that attitudes had a partial mediation role between logical thinking and success. Conclusion and Recommendations: The results showed that the students' attitudes towards to the course have to be positive in order to be successful in Mathematics course. Success grades in Mathematics can be increased by using methods which direct students to think critical and develop these thinking strategies. Improvement in Critical thinking tendencies and logical thinking skills which will enable the students to look at everything from different aspects and will give them opportunity to discover where the formulas and rules came from and how they emerged, can improve the academic success rates of Mathematics which is regarded as a difficult and scary course.