Workers from Anglian Water found the popular accompaniment to Sunday roasts stuffing a sewer in Ipswich, Suffolk on Friday.
The blockage triggered a warning by the firm to only flush the 'three Ps' - poo, pee and toilet paper - down the loo.
Pictures posted on social media show what appear to be several of the baked items clogging up the waterway.
The company tweeted: "Somebody dumped a load of Yorkshire Puddings in an Ipswich sewer.
"Please don't treat sewers as bins, avoid blocked pipes and compost your food waste."
An Anglian Water spokeswoman said: "We always try to encourage people not to put anything down the toilet apart from the three Ps."