The aim of this study was to determine the optimum mixture ratios for composting cattle manure and greenhouse waste, and to ascertain the usability of the value of the area lying below the temperature as a function of time for assessing the success of the composting process. Dairy manure is considerably rich in nitrogen. However, composting with cattle manure alone is not suitable due to its low C:N ratio. For this reason, greenhouse waste was added as a source of carbon in order to balance the C:N ratio of the mixture. Experiments were performed in laboratory- type composting reactors. During the composting process, the process temperatures, CO2 concentrations moisture and organic matter content of the mixtures were monitored.