Women remain significantly underrepresented in engineering education, a cultural milieu which is stereotypically seen as a masculine domain. Laboratory studies and some questionnaire-based studies suggest being numerically under- or overrepresented in student working groups may have an impact on the group work experiences of both female and male engineering students, however this has not previously been adequately explored in realistic engineering education team work settings. Using a quasi-experimental survey design with 217 participants, we document a number of micro-discriminations with respect to women in student work teams in engineering education. Both male and female students seem primed to anticipate potential difficulties arising for female students to a greater extent than for male students, even among high performing students. This suggests a cultural, implicit bias. As such, student group work in engineering programmes may need to be accompanied by teaching and learning strategies which seek to actively question such stereotypes and implicit biases.