Poison dart frogs of family Dendrobatidae are colorful small frogs, which live in tropical rainforests of Central and South America. Their poison is used by American Indians in darts for hunting monkeys and other small animals. The poison of the frogs contains toxins which dull nerves and can produce heart and respiratory failure. The poison secreted by some species ranks among the most powerful animal poisons known. Chemically, it contains animal alkaloids with a wide range of pharmacological activities. More than one hundred alkaloids have been identified in extracts from frog skins. They include batrachotoxins (potent activators of sodium channels), pumiliotoxins (showing myotonic and cardiotonic activity), histrionicotoxins (noncompetitive blockers of nicotinic receptor channels and potassium channels), gephyrotoxin (blocking nicotinic acetylcholine receptor-ion channel complex), and epibatidine (extremely potent and selective nicotinic agonist with strong analgetic activity). Chemical structures of frog toxins are a good inspiration for bioorganic chemistry in seeking biologically active compounds.