Basic peptides such derived from HIV-1 Tat and Drosophila Antennapedia proteins have been utilized as novel carriers for the intracellular delivery of various biopolymers. We have elucidated that these features were shared by many other arginine-rich peptides including various RNA- and DNA-binding peptides, and the presence of a ubiquitous internalization mechanism for the arginine-rich peptides has been suggested. In this review, the potential of the membrane-permeable arginine-rich peptides for the delivery of biopolymers into living cells is reviewed.