Northern Lincolnshire and Goole NHS Foundation Trust was one of 11 trusts put in the improvement regime in 2013 after a government-commissioned review.
It was later taken out when inspectors deemed it had made "real progress".
The Care Quality Commission (CQC) has now raised concerns over emergency, outpatient and maternity services.
The inspection, held between October and December last year, included Scunthorpe General Hospital and Diana Princess of Wales Hospital in Grimsby. Goole Hospital was not inspected as it was rated as good in October 2015.
CQC inspectors identified concerns across a number of services, including:
Ellen Armistead, deputy chief inspector of hospitals at the CQC, said previous improvements had not been sustained, and there had been an overall decline in the quality of care and patient safety.
"For this reason, we have recommended that the trust should re-enter special measures," she said.
"In particular, we would like to see significant improvements to the quality and safety of patient care."
Responding to the report, the trust said it was disappointed but fully accepted the the shortfalls identified.
Richard Sunley, its interim chief executive, said: "We are sorry we have let down our patients, their families and carers by not meeting the quality standards they rightly expect."
He vowed the trust would "make changes with pace".
Two weeks ago the trust was one of three placed in financial special measures in an attempt to help them meet their savings targets.
A hospital trust has become the first in the country to re-enter special measures after inspectors found patient safety and care had worsened.