X-ray excited emission spectra at various temperatures, as well as low temperature glow curves of Czochralski-grown Li2B4O7:Co (LTB:Co) single crystals, have been recorded and compared with the data available for undoped LTB and LTB:Eu,Mn. Although the presence of cobalt does not influence the radioluminescence of the material, it clearly alters its thermoluminescence; specifically, the number of peaks in the glow curve of LTB:Co is reduced as against that of LTB and LTB:Eu,Mn. This observation and its possible interpretations shed new light on the issue of shallow traps in lithium tetraborate crystals. •Radioluminescence spectra of LTB:Co have been measured at various temperatures.•Glow curves of LTB:Co have been recorded between 10 and 300 K.•Trap parameters related to particular glow peaks have been derived.•Doping with cobalt has been found to deactivate some of the traps.