Twenty patients with nasal polyposis, either asymptomatic or with persistent nasal obstruction, were studied prospectively. Fourteen of 18 patients when free of obstructing polyps had no ongoing nasal symptoms. Nasal secretion eosinophilia of greater than or equal to 20% was demonstrated in 19/20 patients. Prick skin tests and RAST were positive to inhalant allergens with poor clinical correlation in 10/20 patients. Mean total eosinophil count and mean total serum IgE, IgA, IgG and IgM were normal. Sinus roentgenograms were consistent with sinusitis in 11/20 patients. Methacholine bronchial provocation was positive in 11/19 patients. Aspirin challenge was negative to 650 mg and 3250 mg in 18/18 and 8/8 patients respectively. Serum salicylate levels two hours post 3250 mg aspirin challenge had a mean of 18.5 mg/dl. HLA typing to the A and B loci revealed no specific pattern. Patients with primary nasal polyposis are characterized by nasal secretion eosinophilia, lack of ongoing symptoms when free of obstructing polyps, increased frequency of cholinergic bronchial hyper-reactivity, increased susceptibility to recurrent or chronic sinusitis, lack of aspirin sensitivity and high frequency of inhalant prick skin test and RAST positivity without correlation to symptoms. These patients may represent a variant of the syndrome involving nasal polyposis, bronchial asthma and bronchospastic reactions to aspirin and related drugs.