The urban greenhouse gas emission (GHG) inventory is an important tool for climate change mitigation. In Brazil, 15 years after the publication of the first municipal GHG inventory, few cities have measured their emissions. It depicts the timid advance in the country's urban climate agenda. In this paper, publicly available inventories were mapped, and then methodologies, emissions and reports were compared, with the aim to identify similarities, divergences and challenges to consolidate this instrument. The results show that the municipal inventories in Brazil are not easily comparable. In many cases, it lacks transparency there are different interpretations of the methodology and gaps of information. The definition of quality criteria and the dialogue among cities may help to refine the tool. Comparative perspective allows the exchange of knowledge between localities with similar profiles, such as Latin American cities. Sustaining discussion on municipal inventories is important for its improvement as a tool to support local interventions.