The rhodium catalysed hydrogenation of a range of N-t-butoxycarbonylindoles has been investigated. In most cases the hydrogenation proceeded smoothly at 200 psi in the presence of acetic acid to give the corresponding N-t-butoxycarbonyl-cis-2,3-dihydroindoles in high yield. Some indoles, in particular those bearing an acyl substituent at C-2 or at C-3, were not selectively reduced at the C-2-C-3 bond.