Police are investigating after an officer accidentally fired a handgun at the Royal Queensland Show in Brisbane on Saturday.

The bullet was unintentionally fired from a Glock inside the police station at the Brisbane Showgrounds at Bowen Hills while a shift change was taking place.

A Queensland Police Service (QPS) spokesperson said the bullet went through the floor, through a wall and into an unoccupied storage area at the end of the building.

"Police took immediate actions to ensure no-one in the area had been injured," it said in a statement.

"The QPS has arrangements in place to mitigate risk to any members of the public during the handling of weapons by officers at the RNA showgrounds.

"This matter is subject to review including whether correct QPS protocols and procedures were followed."

The QPS said officers receive ongoing firearms training, and safely handle their weapons thousands of times each year.

"The number of unintentional discharges is very low," the spokesperson said.

"The Glocks used by the QPS are very safe for operational firearms, which differ markedly from sporting weapons.

"They have safety features built into their design to help prevent unintentional discharges occurring."

An internal investigation will be conducted by North Brisbane District management.