Two new gallo-borates, MGa 2 B 2 O 7 (M=Sr, Ba), have been synthesized and structurally characterized. The structure of SrGa 2 B 2 O 7 (Cmcm, a=11.7260(7) Å, b=8.3745(4) Å, c=5.7062(3) Å, Z=4) has been determined by single-crystal X-ray diffraction (wR(F 2 )=0.089 for 732 unique reflections). BaGa 2 B 2 O 7 (Cmcm, a=11.7434(6) Å, b=8.7076(4) Å, c=5.8038(3) Å, Z=4) has been shown to be isostructural by ab initio structure determination and Rietveld refinement using powder X-ray data (R wp =0.119, χ 2 =2.16). The MGa 2 B 2 O 7 structure, formulated as MGa 2 (B 2 O 5 )O 2 , consists of a framework of corner-sharing tetrahedral (GaO 4 ) chains and pyroborate (B 2 O 5 ) groups with the M atoms filling eight-coordinated framework cavities. It represents a new structure-type for anhydrous borates and, in particular, is structurally distinct from the MAl 2 B 2 O 7 (M=Ca, Sr, Ba) alumino-borate analogs.