The family of Alba Maruri were informed of her death last month and later sent what they were told were her ashes.
But Ms Maruri awoke from a three-week coma in hospital on Thursday and asked doctors to call her sister.
Her family were overjoyed at the news - but are unclear whose ashes they have in their home.
The hospital has apologised for the mix-up. Ms Maruri lives in the city of Guayaquil, the epicentre of Ecuador's Covid-19 outbreak.
Ecuador has been badly affected by the pandemic, with more than 22,000 cases and nearly 600 reported deaths.