We synthesized the Nd-doped Bi 4 Ge 3 O 12 (BGO) single crystals with different concentrations of Nd (0.1, 0.5, and 1%) by the floating zone method and evaluated the photoluminescence (PL) and scintillation properties. In both the PL and scintillation spectra, intrinsic luminescence of BGO was observed at 400–600 nm. In addition, emission peaks due to the 4f–4f transitions of Nd 3+ were observed in the near-infrared range. The 0.5% Nd-doped sample indicated the highest quantum yield of 42.9% among the samples. All the samples showed good linearity between X-ray exposure dose rate and the emission intensity in the NIR range. The lowest detectable dose rates were 0.06 Gy/h in the 0.1 and 1% Nd-doped BGO samples, and that of the 0.5% Nd-doped BGO sample was 0.01 Gy/h.