Today, ergot alkaloids have found widespread clinical use and more than 50 formulations contain natural or semisynthetic ergot alkaloids. They are used in the treatment of uterine atonia, postpartum bleeding, migraine, orthostatic circulatory disturbances, senile cerebral insufficiency, hypertension, hyp- prolactinemia, acromegaly, and Parkinsonism. Recently, new therapeutic – plications have emerged, e.g., against schizophrenia and for therapeutic usage based on newly discovered antibacterial and cytostatic effects, immunomodu- tory and hypolipemic activity.The broad physiological effects of ergot alkaloids are based mostly on their interactions with neurotransmitter receptors on the cells. The presence of “hidden structures” resembling some important neu- humoral mediators (e.g., noradrenaline, serotonin, dopamine) in the molecules of ergot alkaloids could explain their interactions with these receptors . Ergot alkaloids are produced by the filamentous fungi of the genus, Claviceps (e.g., Claviceps purpurea – Ergot, Mutterkorn). On the industrial scale these alkaloids were produced mostly by parasitic cultivation (field production of the ergot) till the end of the 1970s. Today this uneconomic method has been – placed by submerged fermentation. Even after a century of research on ergot alkaloids the search still continues for new, more potent and more selective ergot alkaloid derivatives.