The term "floppy infant" is used for describing children presenting with muscle hypotonia at or shortly after birth. These floppy infants are usually a diagnostic challenge due to the many rare and genetic causes of hypotonia. It is common to start by classifying the hypotonia as peripheral or central, but even from here the path to a diagnosis can be long. This article reviews the literature, mostly retrospective studies done on floppy infants and presents a new simplified algorithm to help guide the diagnostics of the hypotonic children.