Content and language integrated learning (CLIL) approach, introduced by the European Union to promote the teaching of foreign languages and second languages, requires adequate training of future CLIL teachers. This pretest-post-test study analyses the competence to plan CLIL lessons of a sample of students in pre-primary and primary education degrees before (N=56) and after (N=50) taking a CLIL course that is part of their studies. The objective is to analyze the effectiveness of the course by studying the differences between both groups with the CIPMA (Cuestionario de Integracion de los Principios Metodologicos AICLE), a questionnaire, already validated, that specifically measures teachers' competence to plan CLIL lessons. These quantitative results were completed with an analysis of the CLIL lesson plannings that both groups designed as part of the course. From the quantitative analysis carried out, it can be deduced that both groups of students acquire the competence to plan their CLIL lessons and that, despite some differences found in some of the areas of their lesson plannings, the CLIL course provides them with the strategies to adapt the methodological principles of the approach to the idiosyncrasies of their respective educational stages. Despite the limitations of the study, it is concluded that the integration of methodological training in CLIL, together with linguistic training, in both pre-primary and primary education degrees, is effective and necessary for the acquisition of the basic knowledge to plan lessons under this approach.