In this study, we explore the competence of preservice teachers (n = 161) in labelling and creating new cross-sectional human diagrams, based on anatomy knowledge depicted in longitudinal sections. Using educational standards to assess visual literacy and ad hoc open questions, results indicate limited skills for both tasks. However, their competence is particularly poor creating diagrams, where shortcomings were observed not only in visual literacy but in content knowledge. We discuss the misconceptions detected during these assessments. Visual literacy training should be strengthened for these students, as it is a skill that is especially important for future teachers to use in learning, assessing, and reflecting on content in science education. This is particularly important in preservice teachers since they should be fluent in the use of visual teaching tools in teaching anatomy and other content in the biology curriculum.