Police are investigating a complaint of indecent assault on a four-year-old girl at the public toilets at Coolum on the Sunshine Coast last Friday.

Sunshine Coast District Superintendent Darryl Johnson said the offence was serious and police were appealing for the community to help.

"It is definitely a real concern to us, we haven't seen this type of offence in our community in recent time," he said.

"We are appealing to anyone that may know of something to contact police.

"It is in the early stages in the investigation, but it is a serious offence. It is one that we as police, we as the community, family, as mothers and fathers, we want to see that one solved."

Child Protection Unit Officer-in-Charge, Justin Ward, said the incident happened "between 4.30pm and 5.30pm" at the toilet block at Tickle Park at Coolum.

Superintendent Johnson said the child had been medically examined, but not hospitalised.

Superintendent Johnson said police had not released details of the incident or issued a warning as it was "one of the investigative strategies".

"We're working through the information we have and we will get more information out as it comes to hand. All these investigations are handled delicately as it is one we are taking our time to piece together.

"I'm hoping and confident we will solve this and identify the person responsible."

Detective Senior Sergeant Ward said police were looking at CCTV footage in the area.

Superintendent Johnson said public toilets couldn't be singled out as a hot spot for bad behaviour.

"You also see it in places where a lot of people are congregated, such as beaches, parks, shopping centres," he said.

"You can't single out public toilets as hot spots, it is one area though where we need to, as parents, be more vigilant with our kids."