Hull and East Yorkshire Hospital Trust has one of England's highest level of death rates, according to a new survey.
Health research company Dr Foster said the trust was "notable for consistently high [death] rates".
According to the report, Hull and East Yorkshire is one of two trusts in England that have higher-than-expected levels in three out of four mortality measures.
The trust said it was "confident that we provide a safe level of care".
The annual survey records death rates using four measures - deaths in hospital, deaths in hospital and within 30 days of discharge, deaths linked to low-risk conditions and deaths after surgery.
The report said: "Hull has now registered high mortality rates on a number of measures for two years running."
The trust said the figures for deaths following treatment, known as the Summary Hospital-level Mortality Indicator (SHMI), were high due to the fact they provide care for terminally ill patients in a specialist unit at Castle Hill Hospital.
Dr Yvette Oade, executive medical director for Hull and East Yorkshire Hospitals NHS Trust, said: "In the past year we have conducted a complete review of our mortality rating and sought the advice of national experts to help us understand our figures and we are confident that we provide a safe level of care for our patients."