The present study is an attempt to examine the marketing system and consumer preference for processed milk at Mymensingh town, Bangladesh. In addition to that, the study covered the impact of melamine contamination specially in marketing cost, net margin as well as consumer behaviour. The study was mainly based on primary data of 90 samples were purposively selected from Mymensingh town. The findings revealed that impact of total marketing costs of all intermediaries’ increased and net margins decreased during melamine detection.In the present study, preference of consumers for processed milk i.e. powder milk, condensed milk and pasteurized milk were investigated. Consumers’ preference for processed milk was higher than other processed milk (pasteurized milk & Condensed milk) and raw milk. The study will help to knock the door of policy maker in the aspects of processed milk marketing, useful to professionals or different groups involved in the marketing system, researchers, ultimate consumers etc. The study may render as a basis for further study regarding marketing system of processed milk and its consumer preferences as well as the impact of melamine contamination.