Drinking more than guidelines recommend was found to be more common among men and middle-aged adults. And adults in the most deprived areas were less likely to drink above guidelines compared to adults in more affluent places.
Middle-aged adults (aged 35 to 64) were most likely to drink above weekly guidelines (23-24%). Drinking above the weekly guidelines of 14 units was least common in those aged 75 and over (13%).
The survey found 17% of adults reported that they did not drink alcohol, and a further 36% drink less frequently than on a weekly basis.
Some 31% of adults drank more than three units (women) or four units (men) on at least one day within the previous week.
Alcohol Information Partnership director general Dave Roberts said: “Once again, the official data from the Welsh Assembly shows that, on the whole, Wales is a nation of moderate drinkers with a welcome drop in the number of people binge drinking. The number of people reporting to have drunk over the CMO (Chief Medical Officer) guidelines in the past week continues to fall with the most significant declines being among adults under 44.
"The significant improvements in young adults' relationship with alcohol has resulted in more young adults drinking within guidelines compared to their older counterparts. The poorest in society continue to drink less than the wealthiest.”
He said that the partnerships between retailers, licensees, some charities, industry and the public sector – that have projects to educate people about the potential harms of over consumption, to reduce alcohol related crime and to encourage a vibrant and safe night time economy – appear to be “working well”.