Detectives are appealing for witnesses affter the robbery on Friday evening at around 11.15pm on The Old Goods Yard, on Station Road, in Marsden.
The male victim was walking alone and he noticed a man in front of him. He was then grabbed from behind by a second offender and something was held up to his throat.
They demanded money and his mobile phone, which the victim handed over to them and they ran away.
A black Samsung Galaxy S6 phone in a black case and a wallet with cash and cards was taken.
The first suspect is described as a white male, aged 18-20, with short blonde hair and he was wearing a dark Adidas zip up top and jeans.
Detective Constable Craig Foulkes, of Huddersfield CID, said: “This was a terrifying ordeal for the victim, thankfully he was not left with any injuries.
“We are appealing for any information about this incident to assist with our enquiries. If anyone noticed anyone in the vicinity matching the description, I would urge you to come forward and contact the police.
“Anyone with any information is asked to call Huddersfield CID via 101 quoting crime reference number 13170358831 or contact Crimestoppers anonymously on 0800 555 111.”