Significant reduction in inhomogeneous broadening of GaAs/AlGaAs V- groove quantum wires (QWRs) is achieved by growing them on vicinal (001) GaAs substrates misaligned by several degrees with respect to the [1 (1) over bar0] groove direction. Low temperature photoluminescence spectra exhibit QWR linewidths as low as 3.7 meV for subband separation of 41 meV and 3 meV for subband separation of 27 meV. Atomic force microscopy evidences a change in the growth dynamics as compared with QWRs made on exact (001) GaAs substrates. The impact of the different growth dynamics on the wire interface structure is discussed. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2976555]