The assessment of problem-solving competence is an important section in the teaching process in the direction of learners’ competence development at secondary schools in the current period. In this perspective, limited in this article sphere, we set the criteria to assess the problem-solving competence in theme-based learning in Physics at high schools, focusing on building up some assessment tools based on quality criteria, level of behavioural expressions of problem-solving elements, including: (1) Observation checklist (for teachers’ assessment); (2) Questionnaire (for students); (3) Outcome assessment form (for teachers and students); (4) Test (for teachers’ assessment). The assessment helps teachers get knowledgeable of students' competence in applying their knowledge, skills, and experience for solving physics problems. Thence, teachers have adjustments on appropriate teaching methods and techniques.