This article analyses the rationale for the development of a Web-based teacher-upgrading programme and discusses the main issues of in-service professional upgrading of working adults using the WWW. In-service upgrading has been an accepted avenue for retraining practising teachers in Singapore to keep abreast of changing curriculum requirements as well as infusion of information technology in teaching and learning. To cope with the teachers’ busy work schedule and many school commitments upgrading courses were offered to the teachers primarily asynchronously, using the Internet platform with some integrated synchronous sessions. Issues of adult learning in a learner-controlled adaptive learning environment, and life-long learning were addressed through an IT-infused asynchronous mode, providing the much-needed freedom in time management for the course participants. The development also includes delivery of high definition graphics through a customized hybrid system of CD-ROM and Web that addresses image-downloading bottleneck and thereby overcomes a basic problem of distance learning in geo-spatial education. Finally reflections on the attending adult learners’ responses to such an upgrading programme are discussed.