A 19-year-old man was approached by two men on a red scooter in Barnes Lane, Dronfield, at around 2pm on Wednesday afternoon.
The men threatened the victim and pushed him off his motorcycle, a grey and black SYM Symnh X 125, before stealing it and driving away.
The men are both described as white and between 5ft 10in and 6ft tall.
The driver of the red scooter was wearing a dark jacket and hoodie, dark cargo trousers and he had his face covered.
The passenger had blond eyebrows and blue eyes and was dressed in the same way as the driver.
Officers have also released a CCTV image of a red scooter seen in the area at the time, in the hope that someone may recognise it.
Anyone with information should contact DC Tony Hayes, quoting reference number 22*108702.
Facebook – send a private message to /DerbyshireConstabulary
Twitter – direct message the force’s contact centre on @DerPolContact
Website – complete the contact form at www.derbyshire.police.uk/ContactUs
Phone – call 101
You can also anonymously contact Crimestoppers on 0800 555 111.