Inflammation is a host defensive but exaggerates local tissue mechanism in response to various infections, injury or destruction of tissues or any metabolic stimulus. It is a complex phenomenon comprising biochemical as well as immunological factors. The manifestation of acute inflammation is recognized by the symptoms such as redness, swelling and pain. The inflammatory response begins with a release of inflammatory chemicals into the extra cellular fluid, the most important sources of these inflammatory mediators are histamine, prostaglandins and cytokines are products of injured tissue cells, lymphocytes, mast cells and blood proteins. The presence of these chemicals promotes further reactions to inflammation which are redness, heat, swelling, and pain. Pyrimidine derivatives have gained unique importance in the field of medicinal chemistry. Pyrimidine also known as m-diazine is the parent substance of a large group of heterocyclic compounds. Compounds belonging to this group were known as breakdown products of uric acid from very early date in the history of organic chemistry In this book we try to correlate Anti-inflammatory activity with pyrimidine based aryl alkanoic acids.