Broadcaster David Dimbleby cut the ribbon at Eastbourne District General Hospital's new £1.4 million emergency unit.
The Question Time presenter was joined by hospital chiefs, Eastbourne MP Nigel Waterson and Lewes MP Norman Baker at the official opening on Saturday.
Work began on the unit in October last year. It includes a six-bed observation ward and a resuscitation room.
The work was partly funded by a £900,000 Government grant and another £400,000 was raised by the Friends of Eastbourne Hospitals for equipment.
The emergency unit at Eastbourne is one of the busiest in the UK, seeing more than 40,000 patients a year.
It has a 24-hour helipad on site and receives trauma patients brought in by the police and coastguard helicopters.
Hospital trust board chairman Anne Bolter said: "We are delighted that David Dimbleby was able to officially open our new unit.
"The new unit will make a big difference to the services we are able to provide."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article