European Union's Sanitary Landfill Directive foresees that, eliminating of organic waste by environmental friendly methods instead of sanitary landfilling. Therefore, as in Europe, composting of organic waste will be an important alternative for Turkey in following years. To plan, design and operate these composting facilities significant amount of knowledge shall needed. In this study, a 12-month waste profile for the Istanbul Metropolitan Municipality Composting and Recycling Facility, one of the four composting facilities in Turkey, was investigated in detail. Therefore, the flow of the seasonal changes in the units of the facility and its effects on the compost product were determined. Also, the inert content (glass, plastic, metal, etc.) which is important for marketing of the compost was determined and certain strategies were developed for the reduction of the inert materials.