The protective effects of disodium cromoglycate (DSCG) and beclomethasone dipropionate (BDA) on the "delayed nasal response" to allergen challenge (DNR) were investigated in 37 patients with allergic rhinitis. These thirty-seven patients, from a group of 268, developed 43 "delayed nasal responses" (DNR), 16 cases of "isolated delayed responses" (IDNR) and 27 cases of "dual delayed responses" (DDNR), where the delayed response (DLDNR) was preceded by an immediate response (INR). BDA demonstrated significant protective effects on the DNR in both its modifications; however, to a higher degree in the case of the IDNR. DSCG significantly decreased only the INR, being a part of the DDNR, while in the case of the DNR in both its modifications, DSCG was completely ineffective. It is suggested that BDA should be the drug of first choice in allergic rhinitis patients demonstrating the DNR. When immediate responses to the same or other allergens are also present, DSCG should be added at the beginning of the treatment for a temporary period of a few months.