Officers from Rotherham North neighbourhood police team carried out test purchases on 11 shops, all of which didn't sell knives to the cadets.
The team said on Twitter: “We have been out tonight with our cadets on a test purchase operation for knives and bladed articles.
“Pleased to say the 11 shops across Rotherham North tested all passed with flying colours. Staff all on high alert re. selling knives to kids.”
The test purchases were carried out as part of Operation Sceptre – a week long campaign to clamp down on knife crime.