In this review we focus on demonstrating how organic electronic materials can solve key problems in biosensing thanks to their unique material properties and implementation in innovative device configurations. We highlight specific examples where these materials solve multiple issues related to complex sensing environments, and we benchmark these examples by comparing them to state-of-the-art commercially available sensing using alternative technologies. We have categorized our examples by sample type, focusing on sensing from body fluids in vitro and on wearable sensors, which have attracted significant interest owing to their integration with everyday life activities. We finish by describing a future trend for in vivo, implantable sensors, which aims to build on current progress from sensing in biological fluids ex vivo. Since its inception, research in the biosensor field has expanded considerably in parallel with commercial developments, predominantly in glucose sensing. Key parameters for advanced biosensors for continuous monitoring in complex biological environments include devices with favorable mechanical properties, long lifetimes, anti-biofouling, and ease of integration with miniaturized sensor technologies, all at low cost and with minimum power consumption. Organic electronics is a field of research that has rapidly come to the fore for biological applications owing to their literal flexibility and tunability to adapt to challenging performance requirements in complex biological environments. Such devices are widely used for metabolite sensing, and this technology has reached a level of maturity where performance may be compared to state-of-the-art devices and alternative technologies. © 2017 Elsevier Ltd