The crystal structure of nicotinic acid hydrochloride has been determined by two-dimensional x-ray method. The unit cell is monoclinic with a = 7.21 ${AA}$, b = 6.69 ${AA}$, c = 7.54 ${AA}$, ${eta}=100^{circ}$, space group $C{frac{2}{2}}-P2_1$, and contains two formula units. Weissenberg diagrams have been taken along the a, b and c axes with Cu K${alpha}$ radiation and the positions of the atoms have been fixed by means of two dimensional Patterson syntheses, a Fourier projection along the b-axis and trial and error method. The bond lengths are: pyridine ring C-C = 1.38, 1.39 ${AA}$, C-N = 1.34, 1.36 ${AA}$, carboxyl group $C_4-C_6$ = 1.46 ${AA}$, $C_6-O_1$ = l.33 ${AA}$, $C_6-O_2$ = 1.19 ${AA}$. The ring nitrogen atom may be regarded as forming bifurcated hydrogen bond with an oxygen atom $O_2$ of one neighbouring molecule and with a neighbouring chlorine atom, being linked by forming a hydrogen bond with an other oxygen atom $O_1$ of above mentioned neighbouring molecule, in such a way that chains parallel to the c-axis are formed.