The Saturday Night Takeaway star was having dinner at Old Station House gastro pub in Chiswick when a gang started making rude gestures and using mobile phones to film him through the window.
McPartlin, 38, went outside to ask them to leave but the group put him into a headlock, it was reported.
His mother Christine was also pushed to the ground when she attempted to intervene.
A Metropolitan Police spokesman said they were called to incident in Spencer Road, Chiswick, shortly after 8pm on Thursday, March 13.
He said: "No allegations were made and no one suffered any injuries."
The Geordie presenter, who always appears on TV with sidekick Declan Donnelly, last month chopped off the tip of his thumb.
He was figuring out how to use a vegetable-slicing gadget ahead of a Sunday dinner, it was reported.