This book provides a comprehensive overview of the potential use of graphene-based materials in two important societal areas: medicine and the environment. It discusses how new graphene-based materials can be creatively used for biological purposes, for example as delivery vehicles for diagnostics or therapeutics, ultrasensitive sensors, smart responsive substrates for artificial-tissue design and biomarkers. Moreover, it presents new insights into their use as sorbent or phoatalytic materials for environmental decontamination in water and gas-phase desalination membranes and as sensors for contaminant monitoring, giving relevance to the current discussions on the possible toxicological effects of graphene-based materials.