One mum said she took her 10 month old child to the hospital following a fall earlier this week - and was told there was a seven hour wait to be seen.
A spokesman for the hospital said they had faced an extremely busy few weeks - at the busiest peak during the August there were 382 patients, 100 more than at the same period the year before.
Residents are now being urged to only attend A&E in an emergency, and to use other health options if possible.
Phil Walmsley, Chief Operating Officer at North West Anglia NHS Foundation Trust, which runs Peterborough City and Hinchingbrooke Hospitals said: “We have seen a large number of patients attending our hospitals’ emergency departments in recent weeks and our staff are working incredibly hard to see those who need urgent and emergency care. As a result these patients have seen a longer waiting time and this reflects a high level of activity in Emergency Departments across the country.
“Patients in the Emergency Department are triaged and treated in order of highest clinical need, meaning there may be longer waits for patients with less urgent needs.
“The public can help by calling NHS 111 first for help or advice, or by seeking appropriate treatment for minor injuries and illnesses from their local pharmacy or doctor’s surgery.”