A total of 2,121 students dropped out of the eight University Grants Committee-funded universities in the last academic year, with Polytechnic University bleeding the most at 505 departures, taking the tally to a 16-year high.
The latest number was also up 15 percent over 2018-19 and was the highest since 2015-16, during which 1,868 students dropped out, according to UGC figures.
Universities say they usually see students withdraw for various reasons, while the Professional Teachers Union president believes it may have something to do with civic unrest or the pandemic.
PolyU's 505 departures involved sub-degree, bachelor and taught postgraduate programs, up 40 percent from 359 in 2018-19.
City University had 362, while the University of Hong Kong and Chinese University each saw more than 300 leave last year.
The University of Science and Technology recorded 207 dropouts, up 35 percent from 153 the year before.
A total of 1,804 undergraduates dropped out from the eight universities in the academic year 2019-20, up 330, or 22 percent.
HKU had the most dropouts, with 343 leaving - 86 more.
PolyU and CUHK saw 329 and 305 dropouts respectively, both figures up.
There were 37 students in taught postgraduate programs who left in 2019-20, six more than in 2018-19.
But sub-degree programs saw a decline in student dropouts with 280 leaving compared to 343 the year before. Only PolyU, City University and Education University offer sub-degree programs.
Asked about the reason for the high dropout rate, an HKU spokesman said: "We have students withdrawing from studies every academic year. They do not need to give reasons for doing so."
PolyU said it has seen students discontinue their studies every year, with a spokesman adding: "The reasons for withdrawal may vary but usually relate to a change of study plans, health concerns or family issues for individual students."
HKUST said it receives withdrawal applications every year for academic, family or employment reasons, while CityU said students withdraw for various personal reasons.
CUHK said the most common reason cited was to study in other institutions.
Fung Wai-wah, president of the Hong Kong Professional Teachers' Union, believed the increase of dropouts could be related to the unrest and pandemic, as well as the immigration tide.
"I think students would want to finish their studies when they are in university, but immigration could be a factor," he said.
He said while parents and students may not have lost confidence in local universities, they may have opted to immigrate after considering looming developments in the SAR in the long term.