A technique for measuring the emissivity of single, nominally 50-µm-sized tungsten particles at elevated temperatures is demonstrated. Single particles are electrodynamically suspended in the cavity of a cw Nd:YAG laser and subsequently heated by the laser beam. The light emitted by the heated particles is focused onto the slit of a spectrometer. The detector used is an intensified gatable diode array that allows for the collection of time-resolved spectral data. Spectral radiance is deduced by calibrating the system against a standard lamp. Assuming that the relationship between emissivity and wavelength is a smooth function, the particle temperature and emissivity are determined by a curve-fitting procedure involving Planck's spectral radiation law. Experimental demonstration and error estimates of the technique are presented.