This volume contains the proceedings of the NATO Advanced Research Workshop on Band Structure Engineering in Semiconductor Microstructures held at Il Ciocco, Castelvecchio Pascali in Tuscany between 10th and 15th April 1988. Research on semiconductor microstructures has expanded rapidly in recent years as a result of developments in the semiconductor growth and device fabrication technologies. The emergence of new semiconductor structures has facilitated a number of approaches to producing systems with certain features in their electronic structure which can lead to useful or interesting properties. The interest in band structure engineering has stimd ated a variety of physical investigations and nove 1 device concepts and the field now exhibits a fascinating interplay betwepn pure physics and device technology. Devices based on microstruc­ tures are useful vehicles for fundamental studies but also new device ideas require a thorough understanding of the basic physics. Around forty researchers gathered at I1 Ciocco in the Spring of 1988 to discuss band structure engineering in semiconductor microstructures.