School children will be banned from trading footy cards at a suburban primary school to protect younger students.

Principal of Southmoor Primary School in Moorabbin, Marie Kick and the school council president Matthew Ruffin said in a joint statement that the decision to ban cards was made to "protect our little ones".

"Card swapping was becoming very popular, and many of our younger children were not understanding the consequences of card swapping - that you don't get your cards back!" they said.

The primary school will instead be encouraging "healthy activities" such as outdoor games and sport during recess.

President of the Victorian Principals Association, Gabrielle Leigh, said fairness is a guiding factor in handling any fads that hit primary schools.