Staff at Lidl at Highfield in Craigavon were threatened by the men who were armed with knives just before 6pm last night.
A small sum of cash was taken, police said.
No one was injured but staff were left badly shaken.
One of the men was wearing a black hoody and tracksuit bottoms with black and white trainers.
He used a black scarf to cover his face.
The second male was described as stocky and also used a black scarf to cover his face and wore a grey hoodie and tracksuit bottoms.