Objective: Crack cocaine use has increased rapidly throughout Mexico, along with rising HIV and hepatitis C virus (HCV) infections among vulnerable groups. The Tirando Esquina: Interviniendo Muros de Salud (TE:IMS) project uses projection-mapping technology and is the first of its kind to reach and provide health education at an individual and community level to at-risk crack smoking populations in Mexico City. Setting: This intervention project took place in Mexico City. Design: A single-arm design was utilised. Method: The TE:IMS intervention used projection mapping, a community-based art form wherein 3-dimensional (3-D) images, videos and graphics are projected onto buildings in the community. A total of nine projection mapping episodes were projected and health promoters engaged individuals on the street to reinforce messaging and distribute safer crack kits. A sample of persons who use crack (n = 58) were recruited prior to the intervention to complete pretest-posttest evaluation questionnaires. Results: Findings provide evidence of initial effectiveness. Decreases pre- to posttest were found in weekly crack use (p < 0.05), sharing of paraphernalia (p = 0.002) and use of cans as pipes (p = 0.008), while increases were observed in the usage of Pyrex pipes (p = 0.002). While quantitative HIV knowledge assessments did not increase significantly, qualitative data suggest the intervention made a substantial impact on perceptions and knowledge of HIV among those who interacted with the health promoters and saw the projections. Conclusions: TE: IMS was successful in providing health education and harm reduction strategies at a community level to at-risk crack smoking populations in Mexico City. These findings provide evidence for the initial effectiveness of innovative education and harm reduction efforts in this population.