Algae are a broad group of mostly water based photosynthetic organisms which considering the size of the thallus exist as macro algae and micro algae. They are widespread in marine ecosystems and their biomass is a valuable raw material. From the 17th century they have been traditionally used as food in Asia and now more and more in other countries, where mostly brown (Division: Ochrophyta), red (Division: Rhodophyta) and green (Division: Chlorophyta) algae can be found in form of extracts which are used in pharmaceutical, cosmetic and food industry. They are rich in various organic molecules that have beneficial effects on human health and are suitable for usage as supplements. Algae and their extracts are increasingly used in many industries due to their high content of bioactive substances, easiness of genetic manipulation and possibility of cultivation in various conditions. This paper describes characteristic compounds of the highlighted brown, green and red algae in the Adriatic Sea, their properties and applications