Shops across Shropshire have been criticised for selling restricted videos to youngsters.
More than 80% of shops targeted by Shropshire trading standards officers sold 18-rated videos and DVDs to 15- year-old volunteers.
Enforcement officer Richard Morris said he was horrified at the results and warned shop owners to be more vigilant.
However, the results were much better when volunteers tried to buy alcohol or cigarettes.
The two volunteers visited 11 shops in Shrewsbury, Market Drayton, and Whitchurch over two days earlier this month and asked to buy 18-rated videos.
They then visited 34 shops to find out if shop staff were being vigilant when selling cigarettes and alcohol to under-age youngsters.
Mr Morris said: "We were horrified at the results of the video sales as our volunteers only failed to buy 18-rated videos in two of the shops.