The title compound ([NH3(CH2)2NH2(CH2)2NH3]BiCl6, Mr = 527.88 ) has been syn- thesized by diffusion method and its crystal structure was determined by X-ray diffraction method. It crystallizes in orthorhombic, space group P212121 with a = 6.8444(4), b = 13.6329(10), c = 15.6641(12) ?, V = 1461.60(18) ?3, Z = 4, Dc = 2.399 g/cm3, F(000) = 984, μ(MoKα) = 13.132 mm–1 and T = 293(2) K. The final R = 0.0294 and wR = 0.0490 for 2325 observed reflections with I > 2σ(I). Each bismuth atom in the present compound is coordinated by six chlorine atoms to furnish a slightly distorted octahedral geometry. It is worthy to note that each adjacent [BiCl6]3– and [H3dien]3+ entities are linked by hydrogen bonds to form two right- and left-handed helical double-chains running along the b axis. These two helical double-chains are interlaced into quadruple-stranded braid to give rise to a three- dimensional network. The optical absorption spectrum of the compound reveals the appearance of a sharp optical gap of 3.30 eV. The title compound ([NH3 (CH2) 2NH2 (CH2) 2NH3] BiCl6, Mr = 527.88) has been syn- theized by diffusion method and its crystal structure was determined by X-ray diffraction method. It crystallizes in orthorhombic, space group P212121 with a = 6.8444 (4), b = 13.6329 (10), c = 15.6641 12, V 1461.60 18, Z 4, Dc 2.399 g / cm 3, F 000 000 = 984, μ (MoKα) = 13.132 mm -1 and T = 293 (2) K. The final R = 0.0294 and wR = 0.0490 for 2325 observed reflections with I> 2σ (I). Each bismuth atom in the present compound is coordinated by six chlorine atoms to furnish a slightly distorted octahedral geometry. It is worthy to note that each adjacent [BiCl6] 3- and [H3dien] 3+ entities are linked by hydrogen bonds to form two right- and left-handed helical double-chains running along the b axis. These two helical double-chains are interlaced into quadruple-stranded braid to give rise to a three-dimensional network. The optical absorption spectrum of the compound reveals the appearance of a sharp op tical gap of 3.30 eV.