A bumper line-up of eight people - seven men and one woman - are chasing the 2009 president's position, the largest number of candidates in at least 15 years.
They are among 39 people standing for a total of 18 places on the executive.
Voting opened yesterday and closes at 4pm on Thursday.
All voting is done online.
The OUSA executive administers about $2.3 million annually on behalf of about 20,000 University of Otago students.
It is responsible for business activities ranging from a radio station to a book shop, as well as events and welfare services.
Returning officer Kyle Matthews said the OUSA did its best to encourage students to vote, but many students did not bother.
Only 15% of the student body, or about 3000 people, voted last year, down about 5% on the 2006 election.
Students should vote, Mr Matthews said.
"These are the people who are going to represent them next year, but students just don't seem that interested."
At last year's election, Simon Wilson was the top-polling presidential candidate, with the voting option "no confidence" gaining the second-highest number of votes.
This year's election had been widely publicised on campus, all students with email addresses had been individually emailed, and presidential forums had been held, Mr Matthews said.
"There is not much more we can do. We can't make people vote. It is democracy in action."
The position of OUSA president is a full-time one, carrying a salary of $25,000 for the year.
Mr Wilson is not standing again.
This year's candidates are Mohammed Alqumber, Jason Bay, James Burton, Edwin Darlow, Timothy Grigg, Natsumi Izuchi, Jo Moore and Ande Turner.
Ms Moore is the only person to have stood before and polled second to Mr Wilson last year.
Pro-marijuana campaigner Abe Gray is standing for two positions, welfare officer and general executive member.
