This second edition is a comprehensive treatment of all straightforward aspects of Padé approximation, and the authors develop some themes to the level of current research. They extensively cover applications to statistical mechanics and critical phenomena, and there are newly extended sections devoted to circuit design, matrix Padé approximation, computational methods, and integral and algebraic approximants. The new edition also contains a chapter on multiseries approximants. The book contains an extensive bibliography of recent monographs on other specialized material. This succinct and straightforward treatment will appeal to scientists, engineers, and mathematicians alike.