The three-dimensional structures of piroxicam crystallized from two different solvents, toluene and toluene/hexane mixture respectively, are proved identical: $C_{15}H_{13}N_3O_4S,;M;=;331.35$, monoclinic, a = 7.128(1), b = 15.146(2), c = 13.956(2) ${AA},;{eta}=;97.33(1)^{circ},;V;=;1494.37{AA}^{3},;Dx;=;1.472;g/cm^{3},;Z;=;4,;space;group;P2_{1}/c,;Mo;K{alpha}(lambda=;0.71073;{AA})$, F(000) = 688, T = 295 K, R = 0.0611 for 1993 unique observed reflections. The thiazine ring exhibits a half chair conformation. An amide group is involved in an intramolecular hydrogen bond to the hydroxy group, O(17)-H(17)${cdots}O(15){AA}$. The molecule is planar within 2 ${AA}$ with the interplanar angle $127.9(4)^{circ}$ between pyridine and benzene rings. A molecular chain parallel to [011] is formed by two intermolecular hydrogen bonds N(16)-H(6)${cdots}O(11)$ and C(6)-H(6)${cdots}O(11)$, and the molecular chains are held together by van der Waals forces.