4-Hydroxy-2,2,6,6-tetra-methyl-piperidinium trifluoro-acetate.

The title compound, C(9)H(20)NO(+)·C(2)F(3)O(2) (-), is an important inter-mediate in the synthesis of hindered light stabilizers. The piperidinium ring adopts a chair conformation with the hydroxyl group in an equatorial position. The crystal packing is stabilized by O-H⋯O and N-H⋯O hydrogen bonds. The CF(3) group is disordered over two positions with almost equal site occupancy factors.