Acetone extract from aerial parts of Sideritis ozturkii Aytac & Aksoy and its fractions were investigated for its in vivo anti-inflammatory and antinociceptive activities. For the anti-inflammatory activity assessment, carrageenan-induced hind paw edema and for the antinociceptive activity, phenzoquinone-induced abdominal constriction tests were used. Acetone extract of the plant and its phenolic fraction were found to possess significant inhibitory activity on these in vivo models in mice. Ozturkoside A (chrysoeriol 7-O-[2"'-O-caffeoyl-6"'-O-acetyl-beta-D-glucopyranosyl-(1 -> 2)-beta-D-glucopyranoside]); ozturkoside B (chrysoeriol 7-O-[2"'-O-caffeoyl-beta-D-glucopyranosyl-(1 -> 2)-beta-D-glucopyranoside]); and ozturkoside C (chrysoeriol 7-O-[2"'-O-p-coumaroyl-6"'-O-acetyl-beta-D-glucopyranosyl-(1 -> 2)-beta-D-glucopyrano side]) were isolated from the active phenolic fraction. The structures of isolated compounds were elucidated by spectroscopic techniques (UV, IR, 1D- and 2D-NMR, MS). Ozturkoside C showed notable antinociceptive and anti-inflammatory activities without inducing any apparent acute toxicity or gastric damage. Although the activity of ozturkosides A and B were found insignificant in statistical analysis, some inhibitory effect was observed. Accordingly, it is suggested that these components in phenolic fraction might possibly share the antinociceptive and anti-inflammatory activities together. (c) 2007 Published by Elsevier Ireland Ltd.