The design and fabrication of optical waveguides in III-V semiconductors is described. Different epitaxial growth techniques are discussed in the context of their suitability for making the types of layer structure required for optical waveguide devices. In addition, important aspects of the fabrication process, such as lithography and dry etching are described. Ill-V semiconductor waveguide devices based on different physical operating mechanisms are considered, and their relative advantages and disadvantages outlined.