The book 'Acoustics of Wood' is devoted to those aspects related to the development of acoustic methods as an effective means for examining physical properties of wood through an interdisciplinary approach. The main parts of the book are: environmental acoustics, material characterization and quality assessment. In the first part of the book a discussion of the physical phenomena associated with the propagation of acoustic waves in forests is presented. The behavior of wood and wood-based composites as materials used in architectural acoustics is also discussed. The second part was written in response to practical considerations about wood uses. This part provides an introductory understanding of basic aspects related to the theory of waves propagation in anisotropic solids, experimental methods for acoustics and mechanic characterization of wood, examination of wood anisotropy using ultrasonic parameters. In the third part wood quality assessment is discussed. Wood used for musical instruments has the most remarkable quality, with unique acoustic properties. In contrast with wood for musical instruments, free of defects, in common wood the defects are always present. Ultrasonic velocity method, acoustic emission method, acousto-ultrasonic techniques are used for the detection of defects in standing trees, solid wood and wood-based composites. High-energy ultrasonic treatment for wood processing such as drying, defibering, cutting and plasticizing are described in the last chapter.