This review aims to summarise the outcomes of some recent European research concerning toxic cyanobacteria and cyanotoxins, with an emphasis on developments within the framework of the CYANOCOST Action (COST Action ES1105, Cyanobacterial Blooms and Toxins in Water Resources: Occurrence, Impacts and Management). State of the art research and management capabilities in Europe on cyanobacteria have benefitted from input from the pure and applied life sciences, the human and animal health sectors, water engineers, economists and planners. Many of these professional groups have been brought together and they interacted favourably within the framework of CYANOCOST. Highlights of the Action include phycological and ecological studies, development of advanced techniques for cyanotoxin analysis, elucidation of cyanotoxin modes of action, management techniques to reduce cyanobacterial mass development, and research on methods and practices for cyanotoxin removal during drinking water treatment. The CYANOCOST Action has had an active outreach policy throughout its lifetime, resulting in e.g. three handbooks, two special issues in scientific journals and activities in the social media. The many contact channels to end-users, including environmental and drinking water supply authorities, health professionals and the general public are described in this review. Furthermore, the authors have identified a number of gaps in knowledge. Proposed directions for future research in the field of toxic cyanobacteria and cyanotoxins are also discussed.