This study was aimed to identify the relationship between problem solving skills, metacognitive awareness, and mathematics achievement as well as to identify the role of metacognitive awareness as a mediator. This study involved a total of 333 Form Four students from ten secondary schools in Malaysia. Data were collected using questionnaires, while information about mathematics achievement was provided by the school management. Data were analyzed using the Structural Equation Modeling (SEM) technique. Results indicated that all variables correlated significantly with each other, while path analysis revealed the mediation effect of metacognitive awareness between problem solving skills and mathematics achievement. The findings suggest the importance of problem solving skills in influencing secondary school students’ mathematics achievement through the development of metacognitive awareness.