In the title compound (systematic name: 4-bromoacetyl-1,2,3-oxadiazol-3-ylium-5-olate), C10H7BrN2O3, the 1,2,3-oxadiazole ring and bromo­acetyl group are essentially planar [maximum deviation = 0.010 (4) and 0.013 (3) Å respectively] and form dihedral angles of 59.31 (19) and 67.96 (11)°, respectively, with the phenyl ring. The 1,2,3-oxadiazole ring is twisted slightly from the mean plane of the bromo­acetyl group, forming a dihedral angle of 9.16 (24)°. In the crystal, mol­ecules are linked by pairs of weak C—H⋯O hydrogen bonds into inversion dimers with R 2 2(12) ring motifs. The dimers are further connected by weak C—H⋯O hydrogen bonds into an infinite tape parallel to the b axis. In addition, π–π stacking inter­actions [centroid–centroid distance = 3.6569 (19) Å] and short inter­molecular contacts [O⋯O = 2.827 (3) and C⋯C = 3.088 (5) Å] are observed.