The present study describes how teacher design teams (TDTs) in pre-service education were set up to create in-school programs about advertising. A multiple case-study design was employed to reveal what kinds of input-, process-, and output-related factors facilitate or hinder the collaboration of three voluntarily participating teams of pre-service teachers. By combining pre-TDT questionnaire data with an analysis of audiorecorded team design discussions and reflective data collected after the design process, we found that the participating student teachers (1) were unfamiliar with design assignments at the start of the project, but were all intrinsically motivated to take part; (2) especially express practical concerns when designing learning materials, and (3) argue that TDTs positively contribute to their professional development. As this study revealed both facilitating and hindering factors, recommendations for future organization of and research on TDTs in pre-service education are offered.