Due to the rapidly escalating generation of plastic wastes, the development of an effective management strategy is vital to reduce their adverse effects on the environment. The conversion of plastic waste into carbon nanomaterials is a highly viable waste management solution. The growing number of scientific works depicts the potential of the technology for the low-cost synthesis of carbon nanomaterials. However, a detailed examination of developments on the topic is lacking in the literature. Therefore, this paper aims to provide an overview of the publication landscape and knowledge structure for research on plastic conversion into carbon nanomaterials. A bibliometric analysis was performed on 120 publications extracted from the Web of Science. Analysis revealed an increase in the number of publications from 2000 to 2019 with China identified as the most significant contributor. Pyrolysis coupled with chemical vapour deposition is the most widely adopted strategy for plastic waste conversion into carbon nanomaterials, due to the ease in catalyst and reaction conditions control. Most research teams reported successful synthesis of multi-walled carbon nanotubes, graphene, nanoparticles, nanowires and nanoplatelets. Reproducible synthesis of carbon nanomaterials, especially tunable carbon nanotubes, remains a major challenge. This paper provides important guidelines for researchers, funders and policymakers who are key players to develop ambitious projects on the synthesis of carbon nanomaterials from plastics as low-cost carbon precursors.