At around 10.30am on Wednesday (23/9), the victim, a man in his thirties, was walking his dog at Waterhall Park when he was approached by two men.
The men punched and kicked the victim whilst demanding he hand over his phone and wallet.
The victim refused to hand over his property and the offenders made off on foot towards the Lakes Estate.
The victim sustained minor injuries to his face but did not require any hospital treatment.
The offenders are both described as black men around 5ft 9in tall with a slim build. One was wearing a navy blue hooded top, a red t-shirt and dark trousers. The other was wearing a black rain jacket and dark trousers.
Investigating officer PC Siobhan Jones, based at Milton Keynes police station said: “I am appealing for anyone who may have witnessed this incident, or saw the two men matching the descriptions in the area at the time to please get in touch.
“If you have any information, please make a report online or call 101 quoting reference 43200299609.
“Alternatively, if you wish to remain 100% anonymous you can call Crimestoppers on 0800 555 111.”