There have been numerous studies on extinguishing room fires by water mist fire suppression system (WMFSS) in the past decade. Interactions between the fire-induced flow and the discharging water mists were studied. Carrying out experiments with physical models to understand more on the physics of experiment is expensive. Therefore, well-validated numerical models by fire tests are also required. These models are commonly used as an engineering tool for designing water mist fire suppression system. In addition to taking the room as a homogeneous zone, two-layer zone approach is also used. Results based on these approaches were applied to evaluate the performance of water mist system. The application, advantages, limitations, and key results of the theories on predicting the performance of water mist fire suppression system will be reviewed in this article. Language: en