Bioethanol is a versatile transportation fuel and fuel additive that offers excellent performance and reduced air pollution compared to conventional fuels. Its production and use adds little, if any, net release of carbon dioxide to the atmosphere, dramatically reducing the potential for global climate changes. Through a sustained research program and an emerging economic competitiveness, the technology for bioethanol production is poised for immediate widespread commercial applications. This book presents that some bacteria have potential to produce bioethanol from carbohydrate containing substrates and different parameters have an impact on bioethanol production process. This is believed that related information of this book will be helpful to the researchers, scientists and students involved in this field.