Elderly couple missing in Western Australia could be headed for Queensland

A search is underway for a missing elderly couple east of Perth, who police believe may be heading for Queensland.

Carol Lisle, 84, and Ralph Gibbs, 80, were last seen on Sunday night and are believed to be travelling through the state in a white 2006 Mazda B2600.

The great-grandmother is wheelchair-bound, suffers from Parkinson's disease and dementia, and needs full-time care.

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The 84-year-old disappeared from her nursing home in Halls Head on Sunday afternoon with Mr Gibbs, her partner of more than a decade.

Ms Lisle's niece Belinda Hodgkinson said she just wants her aunt back.

"She's not of sound mind. So a lot of the time she doesn't even know where she is."

Ms Lisle and Mr Gibbs were last seen in the Coolgardie area, 555km east of Perth.

West Australian Police think the pair might be headed for Queensland, where Mr Gibbs is from.

The 80-year-old man uses a crutch to walk.

Ms Lisle is described as Caucasian, thin and seen wearing a black and white patterned shirt with grey shorts.

She is in a wheelchair with a burgundy pillow.

Mr Gibbs is described as pale, and of medium build with white hair and blue eyes.

Anyone familiar with the whereabouts, or who have seen the elderly couple are urged to come forward to police.