A man has been stabbed in his face, neck and arm after talking to another man's fiancee on a Sydney street, police say.

The 35-year-old was walking in Burwood about 9pm yesterday when he stopped to talk to a woman standing near the Burwood Police-Citizens Youth Club, police say.

A short time later, a man allegedly crossed the road and asked him not to talk to his fiancee.

The man then attacked the 35-year-old with a sharp object, causing wounds to his face, neck and left arm, police said.