The synthesis, crystal structure analysis and characterisation of a monoazo dye, CI Disperse Orange 61, are reported. The dye crystallised in the triclinic system, space group P-1 with a = 8.859(2), b = 9.899(2), c = 11.417(3)angstrom, a = 78.51(4)degrees, beta = 70.37(3)degrees, ? = 80.46(4)degrees, V = 918.8(4)angstrom 3 and Z = 2. There is only one molecule in the asymmetric unit. The two phenyl rings are oriented at a dihedral angle of 57.87(20)degrees. In the crystal structure, intermolecular CH center dot center dot center dot N hydrogen bonds link the molecules into centrosymmetric dimers, forming R22(30) ring motifs, in which they may be effective in the stabilisation of the structure. The pi center dot center dot center dot pi stacking (interactions) between the phenyl rings may further stabilise the structure, with a centroidcentroid distance of 3.741(4)angstrom.