This paper reports an investigation of problem solving activities of students at university level students. The study focused on the cognitive-metacognitive and affective activities appeared in problem solving process. The cognitive-metacognitive framework was used to analyzed and categorize the written response and free response of interviews probing the students\` cognitive-metacognitive activities. Affective factors were assessed by administering the problem solving survey (Carlson, The emergence of students\` problem solving behavior, 1999). This study provide an insight for the design of problem solving instruction by identifying cognitive, metacognitive and affective characteristics of the students\` problem solving behaviors. The results report that the metacognitive factor were significantly related to problem solving performance interacting with both cognitive and affective factors.