The crystal structure of ethylenediamine dihydrochloride has been determined by the two-dimensional Patterson methods and refined by two-dimensional Fourier syntheses. The unit cell dimensions are a = 4.44${pm}$0.02, b = 6.88${pm}$0.02, c = 9.97${pm}$0.02 ${AA}$, ${eta}$ = 92${pm}$$1^{circ}$. The space group is $P2_1_{/c}$. The carbon and nitrogen atoms in the ethylenediamine itself lie on one plane and its structure has a trans-form with a centre of symmetry in it, and C-C distance of 1.54 ${AA}$, C-N distance of 1.48${AA}$ and C-C-N bond angle of $109.07^{circ}$. The molecules are linked by N-H${cdots}$Cl hydrogen bonds with distance of 3.14, 3.16 and 3.22 ${AA}$ forming three dimensional network. The values of reliability factor for F(okl), F(hol) and F(hko) are 0.11, 0.10 and 0.09 respectively.