In this study, the middle school mathematics teachers' knowledge of division of fractions was investigated through the strategies that they proposed and the problems that they posed for division of fractions. The data was collected from 22 middle school mathematics teachers through the task and semi-structured interviews. The data of this case study was analyzed by content analysis approach. According to the findings, 5 alternative strategies were proposed by 22 teachers to divide fractions. Among these strategies, the most commonly used was invert and multiply strategy and the least are converting fractions into decimal and converting to equation. In relation to the problems that the teachers posed, the findings revealed that more than half of the teachers could not propose appropriate problems. In other words, the teachers had difficulty in generating an appropriate story problem to illustrate division of fractions. These results and implications are discussed and the recommendations are presented in accordance with the findings of the study.