The South Otago A and P Society has staged the event for the district's young women since 1968.
Lorna Cross, who organised that first event and was in charge for the first 20 Show Queen competitions, has never worn the coveted Show Queen crown until this week when 2007 winner Ezra Bellamore helped her try it on for size.
Mrs Cross said she had thoroughly enjoyed her association with the event and encouraged all young Clutha women to consider entering.
Her comments were endorsed by Miss Bellamore, who said taking part in the event was not as hard as she had first thought.
She still kept in touch with most of last year's contestants and said the event was a great way to meet new people and boost self-confidence.
Event spokeswoman Ingrid Keating, herself a Show Queen winner in 1985, said the event remained relevant and of interest to young women of the district.
This year's competition will focus on personal development, and contestants will be involved in a number of activities and events before judging on the main show day, Saturday, November 29.
To celebrate the 40th anniversary, a dine and dance function will be held at the Rosebank Lodge on that night.
"It is hoped that previous participants and winners of the events will join this year's group of girls," Ms Keating said.
All young Clutha women aged between 18 and 24 are invited to enter the 2008 Show Queen contest.
Taking part provided an opportunity to learn new skills, encouraged personal development and built new friendships for the future, Ms Keating said.
Entries are limited to a maximum of 12 people, and the committee had already fielded expressions of interest.
Entry forms are available from Radio Clutha, Big River Radio and Trace's fashion store in Balclutha.
