Mine fill is the material placed underground to fill the voids created by mining excavations. It provides overall large scale ground stabilization while allowing localized pillar recovery. In addition to providing a working floor or back, mine fill has the potential to reduce subsidence and minimize dilution. Mine fill is essential to cut and fill, benching and sublevel stoping mining methods. This paper describes mine fill research carried out at the Western Australian School of Mines (WASM) over the last 10 years or so. The research included cemented paste fill (CPF), cemented hydraulic fill (CHF) and cemented aggregates/rock fill (CAF/CRF) optimization projects for a number of mines throughout Australia and overseas.