The efficacy of a long-acting lubricating and coating agent, phosphocholinamin, in reducing snoring was tested in 12 persons, six of whom received the agent as nose drops and six of whom received a placebo (tap water nose drops). In all subjects, the noise level was measured continuously by using a microphone taped near the cricothyroid notch. In the group treated with phosphocholinamin, the maximum nocturnal decibel level was reduced by a mean +/- SD of 13 +/- 3%, and the snoring index (defined as the number of snores per hour of sleep) was reduced by 25 +/- 12%. In the group treated with placebo, the maximum nocturnal decibel level increased 9 +/- 22% and the snoring index increased 1 +/- 20%. The differences between the two groups were statistically significant (P less than .05). It is concluded that phosphocholinamin can provide a useful medical alternative in the treatment of snoring and that further trials of this agent are indicated.