This book constitutes the refereed proceedings of the 5th Asian Computing Science Conference, ASIAN"99, held in Phuket, Thailand, in December 1999.The 28 revised full papers presented together with two invited contributions and 11 short presentations were carefully reviewed and selected from a total of 114 submissions. Among the topics addressed are programming theory, formal methods, automated reasoning, verification, embedded systems, real-time systems, distributed systems, and mobile computing.