A major concern for rehabilitation and closure of waste landforms on mine sites is their long-term erosion stability. In Western Australia, regulators are requesting landforms remain 'stable' for hundreds of years or the 'long-term'. Therefore, assessing a landform's potential long-term erosion stability requires the use of erosion and/or landform evolution models and defensible erosion thresholds below which rehabilitation landform designs are considered acceptably erosion resistant or 'stable'. The Pilbara Rehabilitation Group, through four member companies-BHP, Fortescue Metals Group, Rio Tinto, and Roy Hill-initiated a project aimed at defining acceptable rates of erosion for rehabilitation landform design for the Pilbara region of Western Australia. As part of the project, a review of information relating to erosion rates on natural and man-made landforms was conducted. This review showed that a wide range of approaches have been used to define acceptable erosion rates, including linking them to rates of soil formation; maintenance of soil quality, which may include considerations of plant/crop productivity, effective soil depth, and soil organic matter and nutrient stores; rates of natural erosion in adjoining areas; potential for gully formation; and water quality impacts. Based on this review, a guideline was developed to define acceptable erosion rates for use in the design of stable mine waste landforms in the Pilbara region. The guideline uses a risk-based approach, with erosion thresholds being linked to the waste material's physical properties and the adverse environmental impacts that may result from landform failure.