In this paper, the achievement of nearly intrinsic InN nanowire is reported. With the use of an in situ deposited In seeding layer, nearly defect-free, non-tapered InN nanowires are grown directly on Si(111) substrates by molecular beam epitaxy. The photoluminescence emission of a single InN nanowire is analyzed, which exhibits, for the first time, a very narrow (∼13 meV) spectral linewidth, a clear band filling effect with the increase of excitation power, and a significant red shift of the peak energy with increasing temperature. Detailed analysis confirms the InN nanowire has a very low residual doping of ∼1 × 1016 cm−3, or less. It is further suggested that there is a small, or negligible level of electron accumulation at the lateral nonpolar surfaces of nearly intrinsic InN nanowires, which is in direct contrast to the commonly observed surface electron accumulation of n-type degenerate InN.