Queues of two miles have been reported this week as the fast-food chain opened 100 stores back up nationwide for delivery and drive-thru.
KFC is operating a limited menu due to a reduced workforce.
Dan Mayneord, from Alvechurch, posted on Facebook on Monday: "Been to work today as I'm a key worker.
"The queue for KFC in Wolverhampton was just ridiculous - a good two miles long.
"One - no I wasn't going.
"Two - how desperate have you got to be for a KFC to join the queue.
"Three - people are obviously struggling with the stay at home bit or they're just stupid."
The restaurants which have opened in the Black Country are: Penn Road Retail Park, Wolverhampton; Bentley Bridge, Wolverhampton; Great Bridge Retail Park, West Bromwich; Leamore Lane, Bloxwich; and Junction 9 services on the M6, Wednesbury.
Stores have also opened in Orbital Retail Park, Cannock and Wrekin Retail Park, Telford.
Some branches are only open for delivery or drive-thru - but all those listed above are open for both.
Drive-thru lanes have opened in a total of 55 stores so far.
All stores were shut on March 25 following the coronavirus outbreak but KFC began reopening stores on Monday.
A spokesman for KFC said: "We know it’s tempting, but please, please don’t all rush at once.
"Delivery remains the best way to get your fried chicken fix – we just want to offer a little more choice to those who are already on the road for essential journeys or on their way home from difficult shifts."