This paper reports on the photo-luminescence spectroscopic results of congruent strontium-barium-mobate (SBN) crystals doped with Cr2O, at cryogenic temperature (20 K). The experimental results reveal the need of re-assignment of the Cr3+ ions defect centres in this material. For first time, a broad emission band in the near infrared region centred at ca. 950 nm is reported. This emission band has micro-seconds decaytime constant and a band-width full-width at half-maximum (FWHM) larger than 1700 cm(-1) and has been ascribed to the vibronically assisted T-4(2) -> (4)A(2) transition. A much narrower emission band centred at ca. 764 nm with milli-seconds decaytime constant and a FWHM band-width of ca. 170 cm(-1) is correlated to the E-2 -> (4)A(2) radiative transition (R-line). (c) 2006 Elsevier B.V. All rights reserved.