Attempts to reform science education have to a minor extent taken into account that gender issues may have an influence on the pupils, their learning and interest. Therefore, examples of using feminist or gender theories for analyzing or planning science education are difficult to find in the literature (Nyström 2007, Sinnes 2006). The aim of this study is to examine to what extent experienced teachers apprehend the gender order within the scientific classroom and also to explore if it is possible to achieve a change in these apprehensions. In-service teachers have unprepared written down their reflections about a real classroom situation, a case, and afterwards got the task of analyzing the situation once again after reading a gender theory. The teachers’ texts have been analyzed in several steps: first, the written material was analyzed to find and form categories of relevance; second, sections were raised that pointed out if the teachers had used the gender theory and in what way they had used it; and third, a comparison was made on an individual level of the teachers’ explanations in the two different tasks. The results show that the participating teachers’ understandings about gender and society were challenged ,which is expressed in different ways in their texts. One group of teachers was able to apply the theory on the concrete classroom event, another group had a discussion on a more general level, while one teacher showed a resistance to the theory and thereby also to the task. The fact that the teachers deepen and widen their interpretation of a real classroom’s event when they get access to a gender theory indicates that this method can be applied in teacher education. The usage of cases can be an instrument to link theories to practical work.