<p>In Finland, involving students in designing educational programmes is a highly valued goal among vocational education and training (VET) providers. This study examined how this ideal is realized through workshop conversations when developing the mental health contents of a vocational leadership programme. The data were drawn from a Change Workshop, a developmental intervention engaging professionals and students from four VET institutions. Utilizing the cultural-historical activity theory and conversation analysis, we analysed students’ involvement in the co-development conversations. We identified six types of conversational actions the students used to participate in co-development conversations: initiating, describing experiences, misaligning and aligning with the talk-in-progress, reporting group discussions, and using acknowledgement tokens. The VET professionals or the workshop facilitators responded to the students’ initiating actions in three distinct ways: by dismissing or disregarding them, by responding empathetically, or by engaging in shared elaboration of the topic. The results highlight that although active student’s participation is a precondition for student involvement, on its own it is insufficient. True involvement requires opportunities for students to influence decision-making during the co-development process.</p>