Diagnosis of allergic diseas was usually based on clinical examination, allergic history and cutaneous tessts to determine the causative allergen. As several in vivo test exitst, we consider necessary evaluation of sensibility and speccificty of skin prick test (SPT) and intracutaneous test (lCT). Occupational Allergic Rhinitis (OAR) is a disease often seen in the factories with high concentration of processing dust as cotton, wool, flax textile. The purpose of this study was to determine the value of SPT and lCT to specific diagnosis of OAR to cotton dust. With 254 chosen patients suffering from OAR to cotton dust and 30 healthy workers in the company were underwent both kind of tests with cotton dust extract. Results: skin prick test: Sensibility was 68.90 percent, mainly in (++) and (+++) degrees. Specificity was 93.3 percent. skin intracutaneous test: Sensibility was 95.28 percent, mainly in (++) and (+++) degrees. Specificity was 90 percent. Sensibility of lCT was greater than sensibility of SPT. No difference wasfound comparing specificity of both tests.