In the crystal structure of the title compound, 5-fluoro-cytosinium picrate, C4H5FN3O+·C6H2N3O7-, one N heteroatom of the 5-fluoro-cytosine (5FC) ring is protonated. The 5FC ring forms a dihedral angle of 19.97 (11)° with the ring of the picrate (PA-) anion. In the crystal, the 5FC+ cation inter-acts with the PA- anion through three-centre N-H⋯O hydrogen bonds, forming two conjoined rings having R21(6) and R12(6) motifs, and is extended by N-H⋯O hydrogen bonds and C-H⋯O inter-actions into a two-dimensional sheet structure lying parallel to (001). Also present in the crystal structure are weak C-F⋯π inter-actions.