The Harris Museum and the grotto in Miller Park are to be lit up purple.
Sunday 1 November sees more than 170 landmarks across the country lit purple to raise awareness of pancreatic cancer.
Councillor Margaret McManus, Preston’s Mayor, is spearheading the event and will be outside the Harris from 7pm on the Sunday.
Carolyn Kay is behind the Preston light up and said: “I lost my sister in January 2010, my mother in October 2010 and my brother in February 2011 to this awful disease.
“It’s important we raise awareness of it, as only three per cent of those diagnosed survive five years or more. This figure has barely changed in 40 years.”