Builders from Leadbitters had provoked curiosity from the youngsters at St Mary's in Yate when they were working on a nearby project.
Liz Jardine, manager of the pre-school, therefore decided to invite construction workers from the company to show the tots the skills of the trade.
The children were also given the chance to put their newfound knowledge of bricklaying to the test, using rounded-off brick trowels to build an actual structure.
Youngsters aged between two and four-and-a-half years of age all took part in the activity, wearing high visibility vests and hard hats.
Speaking to the Bristol Evening Post, Ms Jardine commented: "The children dressed up in their safety gear and looked like proper little builders."
Any young builders who want a brick trowel that will last until their old age could find a W. Rose trowel a good product to consider.
The brand has been manufacturing bricklaying tools for more than 200 years and is widely regarded as a market leader in the sector.