Poly[bis-[µ-1-cyclo-propyl-6-fluoro-4-oxido-7-(1-piperazin-yl)-1,4-dihydro-quinoline-3-carboxyl-ato]nickel(II)].

In the title compound, [Ni(C(17)H(17)FN(3)O(3))(2)](n), the Ni(II) atom exists in a distorted trans-NiN(2)O(4) octa-hedral geometry defined by two monodentate N-bonded and two bidentate O,O-bonded 1-cyclo-propyl-6-fluoro-4-oxido-7-(1-piperazin-yl)-1,4-dihydro-quinoline-3-carboxyl-ate (ciprofloxacinium) monoanions. The extended two-dimensional structure is a square grid. The Ni atom lies on a center of inversion.