Heterocyclic chemistry is of great importance to the medicinal chemists because of their wide utility in various fields. Heterocyclic compounds in general have been very widely used in a number of fields, wherase thiazoles, thiazolidinones and pyrazoles have a unique position in the field of heterocyclic chemistry. The heterocyclic compounds viz, Thiazoles, thiazolidinones and pyrazoles play an important role in, field of medicine, agriculture and industry. The thiazole, thiazolidinone and pyrazole derivatives are used in the medicinal therapy, as antibacterials, diuretics, analgesics, tranquilizers, antihypertensive, antiinflammatory, anticonvulsant, antithrombotic, antituberculous and antitumor agents. In the field of agriculture these derivatives have been used as fungicides, bactericides, herbicides and insecticides. In the field of industry, the most important use of azopyrazolones is in textile industry as fabric dyes for dying cotton, silk, wool, polyesters and acrylic fibers as dyes for leathers, rubber goods, in colouration of paints, varnishes, lacquers, natural and synthetic polymers, inks, multicolour jet printing an hair dying creams.