This book constitutes the refereed proceedings of the International Conference Eco-friendly Computing and Communication Systems, ICECCS 2012, held in Kochi, Kerala, India, in August 2012. The 50 revised full papers presented were carefully reviewed and selected from 133 submissions. The papers are organized in topical sections on energy efficient software system and applications; wireless communication systems; green energy technologies; image and signal processing; bioinformatics and emerging technologies; secure and reliable systems; mathematical modeling and scientific computing; pervasive computing and applications.