The purpose of this study was to examine teachers’ beliefs, perceived competence, and practices of CTL. It also sought to analyze the relationships among these variables as well as their perceived level of CTL practices with respect to their subject areas, teaching experience, and school location. An explanatory sequential mixed methods design was employed. Quantitative data were collected from randomly selected 360 eighth grade science teachers using close-ended questionnaire. The qualitative data were collected using interviews, FGDs, classroom observations, and document review. The quantitative data were analyzed using descriptive statistics, Pearson correlation, EFA, one-sample t-test, independent samples t-test, one-way ANOVA, and multiple regression whereas the qualitative data were analyzed thematically using descriptions and narrations. The findings revealed that science teachers hold both fundamental and context-based beliefs concerning the teaching and learning of science. The quantitative results showed that many teachers felt they are capable of using the context-handling, regulating students' learning, and redesigning dimensions of CTL. However, the qualitative results revealed that teachers lack knowledge and skills in teaching science subjects using CTL dimensions. Moreover, teachers’ practices of CTL dimensions in the science classroom was found to be insufficient and the problem was worse in the emphasis dimension. Although teachers' beliefs and self-perceived level of CTL competence had a significant contribution to CTL practices that explained 16% of the variance, the qualitative data revealed that teachers did not adequately translate their strong expressed beliefs and perceived CTL competence into classroom practices due to various contextual factors. The findings of this study have important implications mainly for science teachers, curriculum developers, and teacher education institutions to have a better understanding about the implementation of CTL in science subjects.