The U.S. Army is engaged in an effort to develop industrial processes that have less impact upon human health and the environment in order to improve sustainability in the Army industrial base and to protect the health of Soldiers and civilian workers. Methylnitroguanidine is under evaluation as a replacement for legacy munitions such as TNT and RDX and is a component of the munitions mixture DEMN. The objectives of this study were to determine the oral acute and subacute toxicity of MeNQ in the rat. MeNQ was not acutely toxic, with no mortalities observed in either male or female rats up to the limit dose of 2000 milligramskilogram mgkg body weight in the acute test. There were also no signs clinical signs of toxicity or morbidity in the subacute 14-day study up to 1250 mgkg-day, the highest dose tested in both males and females. As no signs of toxicity were observed, it was not possible to derive a benchmark dose. These tests indicate that MeNQ has low toxicity over ashort exposure time frame and can be considered as a replacement for legacy munitions.