This includes 3000 participants who didn't get a chance to make it around the lake in 1999 because of severe flooding and damage to the course.
Recent entries from a hometown hero and a Japanese athlete have strengthened the men's field.
Rotorua's Steven O'Callaghan featured in the most dramatic finish seen at Rotorua, in 2009, and has entered for this year's race.
He was set to be the first local runner to win the Rotorua Marathon for many years and was leading the race with 10m to run when he stumbled and fell and was passed by Scott Winton.
O'Callaghan struggled to his feet and finished second, six seconds behind Winton.
He will be a huge sentimental favourite with the big Rotorua crowd expected at the event.
Japanese runner Akiyosho Kamijo is the leading overseas athlete, having run 2h 21m 51s at the Kashiwazaki Marathon in October.
However, Sam Wreford has the fastest marathon time in New Zealand on a certified course for the past 20 years and remains the favourite.
He ran 2h 16m 35s at the Southland Marathon in November and is entering the Rotorua Marathon for the first time.
Wreford also won the Christchurch Marathon in June and took out the New Zealand Cross Country title in Hamilton in August.
Gabriel O'Rourke is the top-ranked women's competitor entered in the full marathon.
She finished second last year behind Liza Hunter Galvan and has been in the medals a total of three times, but has never won Rotorua.
O'Rourke's best recent time was 2h 47m 22s at last year's Christchurch Marathon.
With entries still coming in strong, race organisers say it looks like they will get close to the 3900 total competitors entered last year.