The problem and the aim of the study. Anxiety while teaching mathematics is one key component that may influence both teaching and learning. By investigating the relationship between anxiety levels and metacognitive awareness, the result of such investigation is expected to be able to assist pre-service teachers in overcoming obstacles and developing confidence in their abilities to teach mathematics. Based on that, this study attempts to find out how metacognitive awareness and anxiety in teaching mathematics influence the knowledge of content and teaching of pre-service mathematics teachers. Research methods. The metacognitive awareness and mathematics teaching anxiety questionnaires were used to assess pre-service mathematics teachers’ knowledge of content and teaching as well as their teaching abilities. The research employed a mixed-method approach, which combines quantitative and qualitative research. The quantitative research sample consisted of 135 pre-service mathematics teachers, with 75 being females and 60 being males. In the next step, two research participants were randomly selected to investigate the impact of metacognitive awareness and mathematics teaching anxiety on topic knowledge and instruction in the qualitative research. The two selected subjects were selected based on their knowledge of content and teaching. One had high levels of metacognitive awareness and the other one had low levels of metacognitive awareness, as well as teaching anxiety in mathematics. Results. This study found that the impact of metacognitive awareness and mathematics teaching anxiety on knowledge of content and teaching was confirmed by a multiple linear regression analysis. The results of the multiple linear regression analysis using SPSS 25 showed the influence of metacognitive awareness (X1) and anxiety (X2) on knowledge of teaching and teaching (Y). The regression model Y = – 27,077 – 0.621 X1 + 1,205 X2. According to the results of the multiple regression test, pre-service mathematics teachers with high metacognitive awareness were able to maximize their existing knowledge of content and teaching, whereas those with low metacognitive awareness were unable to do so. Additionally, pre-service mathematics teachers with low mathematics teaching anxiety were able to employ effective ways to maximize knowledge of content and teaching, but pre-service mathematics teachers with high mathematics teaching anxiety struggled to convey knowledge of content and teaching. In conclusion, the study showed that pre-service mathematics teacher students with a high level of metacognitive awareness were more able to explore their understanding of material and teaching to prepare for teaching and learning activities effectively. On the other hand, pre-service mathematics teachers with low metacognitive awareness might find it difficult, as they might struggle with content understanding and instruction. Mathematics teaching anxiety was found to have a considerable negative impact on knowledge of content and teaching. High mathematics teaching anxiety can have an impact on both material understanding and teaching.