Oceans cover a large part of our planet and they are a home for an enormous amount of species. A lot of them are still waiting to be discovered by man, much like the chemicals they synthesize. Marine pharmacology concerns itself with the study of these chemicals and their potential use in medicine. Origin in marine species is for the most part the only thing this large and diverse group of substances have in common, so the spectrum of possible applications is quite wide. Many of these substances have a unique mechanism of action, offering new therapeutic possibilities. Although just a few of them are used in a clinical practice today (e.g. eribulin, cytarabine), the future looks quite promising. Current clinical trials focus mostly on the therapy of cancer, but trials for therapy of pain or Alzheimers disease and many others are also underway.Key words: marine pharmacology.