During the last years, considerable efforts were produced on the study of algal toxins, due to recent increases of toxins number, algal vectors and impacted geographical areas. Whatever the biotope type (fresh or marine waters) and despite wide variations in phycotoxins structures, detection difficulties are similar : global but low sensitivity tests or, conversely, sensitive but too specific bioassays, limited number of available standards. Besides, epidemiological data are limited, recent and often resulting from the implementation of regional or national monitoring networks. Modes of action are well-known for the most frequently occurring compounds but poorly investigated for chronic effects. While some similarity in toxinogenesis regulation can be noticed, it appears that food web contamination processes are tightly dependent on the sensitiveness of producing organisms, as well as on habitats (benthic or pelagic). All stressed gaps in available knowledge ascertain the need to improve consumer risk prediction tools.