Glass ionomer cements have been commercially available for 10 years. Research has led to the production of improved formulations and the material is now advocated for use in a number of clinical situations. The aim of this review is to bring together the findings of published studies that provide information on the clinical uses and performance of this material. The opening section looks at the biocompatibility of the glass ionomer cements. Their clinical handling and techniques for use are then discussed. Finally, specific clinical uses are considered in the light of published clinical data. The glass ionomer cements appear to offer the profession many benefits and they are proving to be successful in a variety of clinical situations. Improvements in strength, abrasion resistance and colour matching will widen the scope of their application still further.