More than 10 million people watched the long-running soap Coronation Street on Monday as Hayley Cropper, sick with incurable pancreatic cancer, took an overdose of drugs and died peacefully in the arms of her loving husband Roy.
Some praised the storyline for its sensitive handling of terminal illness and death, but others said it risked encouraging suicides.
Right-to-die campaigner Jane Nicklinson, whose late husband suffered from locked-in syndrome and waged a court battle for the right to have a doctor help him end his life, said the story had "done our cause proud."
But anti-euthanasia group Care Not Killing said that the programme was "in great danger of normalising an occurrence that is actually very rare indeed".
Television network ITV said writers and producers had consulted with the suicide-prevention group the Samaritans and cancer charities about the scripts.
The Samaritans said calls to its telephone help-line after Monday's show were up by almost a third compared to the same period last week.
But chief executive Catherine Johnstone said the makers of Coronation Street had covered the issue sensitively and acted responsibly by consulting the organisation about the plotline.
Over the years shows like Coronation Street and its rival EastEnders have reflected debates in society on issues ranging from gay relationships to racism.