This study aimed to determine the optimum mixture ratio of pine cones, goat manure and wheat straw and obtained optimal Free Air Space (FAS) values for composting. For this aim, pine cones were added at different ratios into goat manure and wheat straw mixtures. So, the FAS value of mixtures was fixed at four different levels. According to the results, the highest organic matter degradation and temperature value were obtained at the mixture ratio of 11% pine cones, 45% goat manure and 45% wheat straw, FAS value of this mixture was 32.8. (c) 2006 Elsevier Ltd. All rights reserved.