Although it is widely accepted that nasal obstruction leads to snoring and sleep apnea, the relationship between these variables is not clear, mainly because of the lack of studies in which nasal resistance (Rna) and snoring were measured concurrently. The authors studied eight nonapneic snoring men with healthy noses by nocturnal polysomnography that included quantitative assessment of snoring and concomitant nasal resistance. In six of these eight patients nasal resistance increased during sleep, but there was no significant change for the group as a whole between wakefulness (0.209 +/- 0.224 Pa/cm3 per second) and sleep (0.292 +/- 0.203 Pa/cm3 per second). Linear regression analysis showed no significant correlation between sleeping nasal resistance and snoring index (partial R2 = .44, P = .071). We used each subject as his own control and compared the snoring profile at a time during sleep when nasal resistance was at its highest (0.550 +/- 0.375 Pa/cm3 per second) and lowest (0.146 +/- 0.090 Pa/cm3 per second) levels. Despite the significant (P < .01) differences in nasal resistance, they were not reflected in the number of snores or their sound intensity. It is concluded that nasal obstruction during sleep is not correlated significantly to frequency or intensity of snoring during exclusively nasal breathing.