This is a clear, accessible and up to date exposition of modular representation theory of finite groups from a character-theoretic viewpoint. After a short review of the necessary background material, the early chapters introduce Brauer characters and blocks and develop their basic properties. The next three chapters study and prove Brauer's first, second and third main theorems in turn. The author then applies these results to prove a major application of finite groups, the Glauberman Z*-theorem. Later chapters examine Brauer characters in more detail. Navarro also explores the relationship between blocks and normal subgroups and discusses the modular characters and blocks in p-solvable groups. Finally, he studies the character theory of groups with a Sylow p-subgroup of order p. Each chapter concludes with a set of problems. The book is aimed at graduate students with some previous knowledge of ordinary character theory, and researchers studying the representation theory of finite groups.