Composting is a controlled bio-oxidative process of decomposition of predominantly microbiological organic solid waste that results in the formation of the biocompost which is a stable product with appropriate characteristics for different uses. Biotechnology is a very useful farameta in the viability of processes and services, having been used in the composting process aiming to accelerate the bioprocess through the cultivation, selection of specific microorganisms in the degradation of the substrate and optimization of parameters such as C/N ratio, humidity, temperature, pH. This book opens good prospects for accelerated composting of organic solid waste, a process that is usually performed in a traditional way, requiring a long time (about 90 to 120 days) until the acquisition of compost. It is a biotechnology study developed under the guidance of Prof. Dr. Paulo Fernando de Almeida.