The present invention concerns cell-penetrating peptides which comprise an amino acid sequence consisting of GLX9RALX9RX1LX2RSLX9X3X4X5X6X7X8 (SEQ ID No: 1), wherein X1 is A, L or G, X2 is W or none, X3 is R or K, X4 is K, L or S, X5 is L or K, X6 is R or W, X7 is K or S, and X8 is A, V or Q, and X9 is W, F or Y. These CPPs can be used as vectors for delivering nucleic acids and/or proteins and/or peptides to cells, in vitro or in vivo.