This study reports the evaluation of a lesson series, developed in collaboration with teachers and experts, to generate a research-based solution for teaching critical thinking through Socratic dialogue in secondary vocational education. The lesson series has been evaluated for feasibility and tailoring to different target groups of students by five citizenship education teachers and 85 students. Data consisted of self-report questionnaires by teachers and students, complemented with observations of lessons. Results show that lessons based on Socratic dialogue for teaching critical thinking to students in secondary vocational education are considered a promising educational intervention. Teachers considered the lessons as feasible and well-tailored to their students and were able to implement the lessons in their classrooms. Students were motivated to participate, and their motivation did not decrease significantly during the lesson series. At the same time, students tended to be more motivated when the value of learning to think critically for their future profession was clearly substantiated. Practical implications from the evaluation of the lesson series were that, in addition to participating in Socratic dialogue, students need clear learning objectives and short assignments to remain active.