A high sensitivity thermoluminescence (TL) spectrometer capable of producing 3D isometric plots of TL intensity against wavelength and temperature is described. The use of two multichannel detectors (imaging photomultiplier tubes) with matched gratings gives optimum detection efficiency for TL signals over a wide spectral range (200-800 nm), and at heating rates normally used for standard TL applications. Spectra have been recorded from dosimeter phosphors and minerals at low dose levels; several examples are given.