Arthritis is a generic term used for inflammatory joint diseases that may presented as destructive and deforming type affecting the joints which may be associated with systemic disturbances; it is widely distributed in every part of the world. Different methods for induction of arthritis in animals are found; the easiest one is the chemically induced arthritis by dextran and formalin solution (0.1 ml of solution intra-articularly at the right knee joint of each rabbit). The aim of this study was to explore the potential anti-inflammatory activity of some drugs (namely nitroglycerin and enalapril), and some medicinal plants extracts (namely licorice and black cumin) against chemically induced arthritis, then comparing their effects with the effects of steroidal drug (dexamethasone) and non steroidal anti-inflammatory drug (lysine acetyl salicylic acid) which have been used in clinical practice to subdue the inflammation. Seventy domestic local rabbits were used in this study, they were divided into seven groups, and each one contained ten rabbits. The anti-inflammatory activity and the efficacy of the tested agents were evaluated in view of five clinical parameters (localized signs of inflammation, erythrocyte sedimentation rate, temperature, total WBC count, and WBC counts in synovial fluid aspirate) for interval of fourteen days after administration. The aqueous extract of licorice and nigella sativa produced a significant inhibitory effect against localized signs of inflammation when they used in traditional doses, with percentages of 100% of rabbits that have a localized signs of inflammation at the first day of the study then reduced to (20% and 30%) respectively at the end of the study, they also produced a significant anti-pyretic effects with percentages of rabbits that have a significant fever (80% and 90%) respectively at the first day of study then decreased to 0% at the end of the study. Both extracts of licorice and nigella had a significant effect in keeping the ESR values with mean readings of (1.5±0.55 and 1±0.22) respectively at the first day of study then settled at (1± 0.28 and 1±0.45) respectively at the end of this study, also a significant suppressing effect on total WBC count was seen except in nigella sativa, with mean readings of (2.4±0.32 and 3.5±0.25 cell/mm3)103 respectively at the first day of study then changed to (2.5±0.18 and 4i0.22 cell/mm3) 103 respectively at the end of the study, both extracts had a significant suppressing effect on WBC count in synovial fluid, with mean readings of (6±2.7 and 5±2.3 cell/mm3) respectively at the first day of study then settled at (4±1.3 cell/mm3) for both of them at the end of the study. While the enalapril and nitroglycerin have no significant anti-inflammatory effects on these parameters as compared with dexamethasone and lysine acetyl salicylic acid which produced significant effects on all the parameters when they used in traditional doses.