More than a quarter of students taking computer studies courses do not complete them, according to the HEA report.
Computer courses have the biggest problem in the university sector despite the dependence on information technology in the economy, the report reveals.
Almost 27 per cent of computer studies students dropped out, compared to 22 per cent for science courses and almost 20 per cent for engineering/architecture courses.
The HEA said specific studies are needed on the high rates in computers and science.
Trinity College had by far the worst retention rate in computers, with 32.4 per cent dropping out.
This compared with its overall dropout rate 16.2 per cent.
Trinity was followed by NUI Galway (28 per cent), DCU (26.1 per cent) and UCC (26.1 per cent).
Trinity's main computer course - computer science - had a 32.7 per cent rate, with male and female students dropping out in almost equal numbers. Almost 30 per cent of students also graduated late.
Trinity's computer science and linguistics course had a 31.2 per cent rate, with three times as many male students dropping out.
Other colleges also had major difficulties retaining students. At UCC almost 34 per cent dropped out of its BA in computer studies.
Its overall dropout figure was reduced because its B.Sc in computer studies performed better, with only 18.2 per cent dropping out.
DCU's computer applications course experienced a 24.6 per cent rate and its applied computational linguistics had a 20 per cent rate.
There were wide disparities in the rates at the University of Limerick. While only 8 per cent opted out of its information technology course, its computer systems course experienced a 33.3 per cent rate.
The university, in its response to the HEA, said there were "worrying" non-completion rates on this course and it had done a survey on the problem.
It was also placing emphasis on putting students into small manageable groups and monitoring them closely during tutorials and practicals.
The university also referred to problems with maths for technology and science students. It said higher-level maths was a relatively reliable indicator of ability, but even a B at ordinary level "did not ensure basic mathematical competence".
Consequently it gave first year students a "diagnostic test" and those who were weak were given special tutorials, it said.
Science in many colleges also suffered from poor completion rates. NUI Maynooth (42.5 per cent) was the worst, followed by DCU (33.5 per cent).
Included under the science heading, in addition to the mainstream subjects, was agricultural and food science.
Other areas had more modest rates with law (7.1 per cent) and medicine/dentistry/ veterinary medicine (7.3 per cent) doing the best.
With a rate of 19.6 per cent engineering/architecture suffered serious problems too. The University of Limerick was the worst in this category with 27.2 per cent, followed by DCU with 19.4 per cent.