Researchers from the University of Exeter in the UK gave 88 social drinkers a word-learning task.
Participants were then split in two groups at random and told either to drink as much as they liked (the average was four units) or not to drink at all.
The next day, they all did the same task again - and those who had drunk alcohol remembered more of what they had learned.
The researchers stressed that this limited positive effect should be considered alongside the well-established negative effects of excessive alcohol on memory and mental and physical health.
"Our research not only showed that those who drank alcohol did better when repeating the word-learning task, but that this effect was stronger among those who drank more," said Celia Morgan, professor at the University of Exeter.
"The causes of this effect are not fully understood, but the leading explanation is that alcohol blocks the learning of new information and therefore the brain has more resources available to lay down other recently learned information into long-term memory," said Morgan.
"The theory is that the hippocampus - the brain area really important in memory - switches to 'consolidating' memories, transferring from short into longer-term memory," she said.
The effect noted by the researchers has been shown under laboratory conditions before, but this is the first study to test it in a natural setting, with people drinking in their homes.
The study was published in the journal Scientific Reports.