Interest in colloidal silver, a commercially available naturopathic product, was sparked after clinical improvements were seen in a number of recalcitrant CRS patients who sprayed the agent intranasally. Silver has long been used for its bactericidal properties, as it is one of the most toxic elements to microorganisms.7 Silver-impregnated dressings and catheters are currently used in the treatment of burns, ulcers and chronic wounds. Clear advantages of silver over modern antibiotics include broad spectrum activity against Gram-positive and Gram-negative organisms, fungi, protozoa and some viruses as well as the general absence of resistance developing in a number of bacterial species.7,8 In addition, silver has been shown to have activity against Pseudomonas aeruginosa biofilm development.9