Substituted aryl aminomethyl thiazole ureas and analogues thereof that act as inhibitors of viral capsid formation, including HIV capsid formation, are provided here. Generally the virus capsid formation inhibitors described herein are compounds of Formula I ##STR00001## wherein the variables A, R.sub.1, R.sub.2, R.sub.3, R.sub.4, X, Y, Z, A.sub.5, A.sub.6, A.sub.7, R.sub.8, R.sub.9, R.sub.12, and R.sub.13 are defined herein. Pharmaceutical compositions comprising such compounds and methods of treating animals infected with a virus having a capsid protein are provided herein. Methods of using such compounds to treat human patients infected with an HIV virus and reducing the mortality of AIDS are also provided herein.