Density is an important property of ionic liquids (ILs) that is required for process and product design. A recent article by Gardas and Coutinho (2008) reports the extended density correlation of ILs in wide ranges of temperature and pressure. However, they validated the density correlation only for ILs based on the following cations: imidazolium, pyridinium, pyrrolidinium, and phosphonium. The objective of this study is to validate the density correlation for ammonium-based ILs. The density model was tested against experimental densities available in the literature of ammonium-based ILs at a wide range of temperatures (273.15-393.15 K) and at 1 atm (0.1 MPa) of pressure. The results show that the predicted densities are in good agreement with available experimental literature values. The average absolute relative deviation (AARD) is 1.57%.