Purpose: This study aims to analyse the self-perception of future secondary school teachers (FTs) of biology about their education for sustainable development (ESD) competencies and evaluate the competence profile they develop in their educational proposals. Design/methodology/approach: A mixed methodological approach was used to analyse 162 FTs' ESD action competencies as proposed by UNECE. Firstly, a six-point Likert-type scale questionnaire is used to explore their self-perception of the level of acquisition of these competencies. Then, a rubric is applied to analyse the competence profile when designing educational proposals to address socio-environmental issues related to consumption and waste generation. Besides descriptive analysis, inferential statistics were used to assess the significance of the differences detected between the competencies. Findings: FTs self-perceive a partial acquisition of ESD action competencies, in line with their competence profile. Where they recognise and show significant difficulties is in assessing learning outcomes in terms of changes and achievements. Similarly, their best perception and competence profile is achieved in the approach to contextualised situations in the students' lives. There are also some discrepancies between their perception and their profile. In particular, FTs regard themselves as very competent in considering different dimensions and perspectives of the issues, but this is precisely where they reveal a lower competence profile. Originality/value: This study applies a fully replicable rubric for the assessment of teachers' ESD competencies when designing proposals to address socio-environmental issues. This assessment allows one to approach the sustainability competencies that they will promote in their classrooms.