A low-afterglow, 10B-doped neutron-sensitive ZnS/10B2O3 scintillator was developed. The developed ZnS phosphor has a primary decay time constant of about 60 ns with a low afterglow. The developed scintillator exhibited a mean afterglow height of 4% relative to the peak at 1 μs after the peak, which is half that of a commercial ZnS/6LiF scintillator manufactured by Applied Scintillation Technologies. The count-rate capability of a wavelength-shifting-fibre-based detector was increased to 30,000 cps by implementing the developed scintillator from 5,000 cps with the commercial scintillator.