Although previous studies have proven the usefulness and effectiveness of geographic information system (GIS) use in the K-12 classroom, the rate of teacher adoption remains low. The identified major barrier to its use is a lack of teachers' background and experience. To solve this limitation, many organisations have provided GIS-related teacher training using various GIS learning materials. However, most materials have been developed without much consideration for the "users" of these materials. This article introduces a user-centred design (UCD) approach to design and develop GIS learning materials in collaboration with a group of teachers to assist teachers in learning about and implementing GIS effectively in their classrooms. To illustrate this approach, the author presents a case study that involves developing GIS learning materials for middle school social studies teachers in Colorado, USA. As a result, the majority of teachers reported that UCD-based materials were easy to learn and follow.