Leslie Ash is to reprise her role as Vanessa Lytton during a guest appearance on Casualty.
The actress, 61, last played the character of the former hospital chief executive in sister show Holby City in 2010.
She will appear in an episode of the long-running BBC programme this summer.
Ash said: “I’m thrilled to be joining the Casualty team for this episode and stepping back into Vanessa Lytton’s shoes.
“It’s been a few years since she graced the wards of Holby City hospital and I’m excited for viewers to see what’s in store for her.”
The actress also told OK! Magazine she will be returning to the programme as a patient, adding it is “a great little storyline and it’s given me the chance to be back on set again”.
Ash, 61, has also starred in Men Behaving Badly, Quadrophenia, Doctors and Judge John Deed.
Casualty airs on BBC One on Saturdays.