The use of endocytic uptake pathways to deliver poorly permeable molecules into mammalian cells is often plagued by entrapment and degradation of material in late endosomes and lysosomes. As a strategy to prevent the exposure of cargo to these highly hydrolytic membrane-sealed compartments, we synthesized derivatives of the membrane anchor N-alkyl-3 beta-cholesterylamine that selectively target linked compounds to less hydrolytic early/recycling endosomes. By targeting a pH-dependent membrane-lytic dodecapeptide and dislufide-linked flurophore to these compartments in Chinese hamster ovary cells or Jurkat lymphocytes, membranes of early-recycling endosomes were selectively disrupted, resulting in cleavage of the disulphide and escape of the fluorophore into cytosol and nucleus with low toxicity. The ability os appropriately designed N-alkyl-3 beta-cholesterylamines to deliver cargo into and release dislufide-linked cargo from relatively nonhydrolytic early/recycling endosomes may be useful for the delivery of a variety of sensitive molecules into living mammalian cells.