Grampian Police stressed that far from being just a toy, they are classed as a motorised vehicle and have warned parents that by not using one properly, a child could end up being injured or even in the sheriff court.
Mini motos are miniature replicas of adult motorcycles — driven by either petrol engines or electric engines — and can reach speeds of up to 30mph.
Police said a rider should have proper training and wear protective clothing including a crash helmet, leather gloves, boots and a suitable leather jacket and trousers. They said a lack of protective clothing could lead to serious injuries.
A police spokesman said: "Even at relatively low speeds they could still suffer a serious head knock, broken bones or nasty cuts, depending on the surface they land on.
"Any area of rough ground that you use could have bits of wood, metal, glass or stones lying around that you might not see, until it is too late to avoid them.
"If you use it on a public road, you could collide with another vehicle, or you could strike your head on the kerb or the road. "Riding a mini moto safely is fun but being a patient in a hospital's casualty ward certainly will not be. A 14-year-old boy in Grampian suffered a broken collar bone earlier this year."
He said it was illegal to use a mini moto on any public road or pavement, no matter how quiet the road was.
"The rider could be charged by the police under the Road Traffic Act and possibly have to go to court, where they could be given a fine," he said. "Several youngsters in Scotland have already been prosecuted and fined for illegally using them on streets around where they live."
He said anyone who owned a mini moto should only use it in their own garden or on an area of private land, with the landowner's permission.
The Deeside Activity Park at Dess, Aboyne, has a go-kart track suitable for use by mini moto riders.
Owner Ken Howie said: "The most important thing if folk are considering buying one, is buying the helmets, gloves and knee pads, at the very least.
"Then they need to find the appropriate place to race them. Since Easter we've opened our kart racing circuit for guys with their own bikes and it's been extremely successful. In fact, the police came up here one day with their speed detectors and sat at the race circuit giving people an idea of how fast their bikes were going.
"What we've done over the course of the year, every three to four weeks, is run a championship race day where juniors and seniors of different abilities could put themselves up against others in a safe and controlled environment."
Ken said the last such race day was held on Sunday, November 20, and will not re-start until the spring when the weather has improved substantially.
He said their track was only used by those who had their own mini motos, as the park did not have any bikes to hire out.
Ken said a new year novices mini moto day was to be held on Tuesday, January 3, for anyone who had received a mini moto for Christmas and wanted to learn the basics in a safe environment. For more details, call the park on (013398) 83536.
The Scottish Mini Moto Shop at 579 George Street, Aberdeen, (01224) 647287, can also offer advice on where to use them safely.
Leslie Harrold, senior road safety officer for Grampian Police, said: "Riding a mini moto or a motorised scooter can be great fun, if it is done safely and legally.
"Parents must be aware of the real dangers their child can face when using these machines. They can travel much faster than a bicycle and can inflict more serious injuries on a rider, if they fall off.
"Always ensure your child is wearing proper protective clothing and using the bike in safe manner, at a legal location.
"Don't end up spending your festive period going to the hospital to visit your child, after they have injured themselves on one of these. Have a safe and enjoyable Christmas."