Teamwork is increasingly seen as an important component of engineering education programmes. Yet, prior research has shown that there are numerous ways in which teamwork is gendered, and can lead to negative experiences for women students. This article presents the first interview findings on professors' perspectives on gender and teamwork. Semi-structured interviews were conducted with 39 engineering professors to determine what and how they thought about gender in engineering and engineering education. For this article, the parts of the interviews about teamwork are analysed. We conclude that professors need tools to help them facilitate gender-inclusive teamwork, and those tools must address the beliefs that they already hold about teamwork. The findings raise questions about the adoption of evidence-based instructional practices and suggest current teamwork practices may exacerbate gender inequalities in engineering.