Teotihuacan, the great metropolis of the Central Mexican highlands, has often been characterized as a state without a writing system. This paper redresses this notion and provides an overview of the city’s writing system and weighs in on its state of decipherment. The corpus of texts is defined and outlined as are its media and contexts. The geographical distribution of the writing system is considered, identifying the localities that define the heartland of Teotihuacan writing and culture, as well as more distant sites and enclaves elsewhere in Mesoamerica where examples of Teotihuacan writing have been found. The temporal distribution is also appraised before going on to present the underlying graphic characteristics of the writing system, leading to an appraisal of the sign inventory, showing clear correspondences to other Mesoamerican logophonetic writing systems. A synopsis of previous work on the writing system is presented in a historical précis, before considering candidate languages of the script and features of the underlying language recorded in the writing system.