Street art is visual art in public spaces — public art — created for public visibility. Street art addresses a massive and extremely diverse audience: everyone in a city. Using a case study approach, this article explores: 1) the extent to which science-inspired environmental street art can be considered a vehicle for science communication in less tangible science contexts and institutional settings — on the street — and 2) the strategies that street artists deploy to communicate their environmental messages through large-scale painted murals. This article clarifies how street art can be understood as a means of creative grassroots environmental communication. It shows that, and how, street art can encourage agency in pro-environmentalism and help to develop our relationship with sustainability.