New National Union of Students (NUS) Scotland figures show only 115 out of a total of 1430 students on Bachelor of Law (LLB) courses in 2010/11 were from the 20% most deprived backgrounds – just 8%.
Nearly 13% of all university entrants come from the 20% most deprived backgrounds.
In the wake of the figures, Scottish universities have been urged to accept more students from college with HND qualifications on to law courses to widen access.
Last year, a £1.8 million scheme to increase the number of students from deprived areas entering professions traditionally seen as middle-class was attacked for a lack of ambition.
The scheme, which funds widening access projects at universities including Edinburgh, Aberdeen, Dundee, Glasgow and St Andrews, will result in only a few dozen additional students being recruited from under-represented groups.
The Scottish Government has now introduced outcome agreements with the sector which place a requirement on them to take more poorer students in return for funding.
Robin Parker, president of NUS Scotland, said: "We know universities and the legal profession have a role to play in making access fairer.
"The number of students accepted into LLBs with college backgrounds could be a window into how well represented students from Scotland's poorest communities are.
"With figures showing students from Scotland's poorest communities are significantly under-represented, it's clear more needs to be done to ensure fair access.
"Universities need to be working with colleges to ensure that HNC and HND courses are structured to help students complete LLBs without unnecessary delays."
A spokeswoman for Universities Scotland said institutions accepted a variety of entry qualifications for undergraduate study, such as HNDs.
She said: "There has been steady growth in the number of college students that have moved on to university, skipping the first or second year, as universities recognise prior study.
"Competition for access to medicine, law and the other professions at university is fierce. While the HND will be recognised for many of these degrees, to gain a place candidates will also have to be able to demonstrate their enthusiasm and commitment to the subject as with any other applicant.
"The ancient universities are highly focused on widening access to the professions and work together through a successful programme which supports and encourages state school pupils from S4 onwards."
While some universities have a strong track record for recruiting HND students, others have attracted fewer.
In the past five years, Glasgow University has admitted 22 students on to its law course with an HND, Edinburgh Napier has admitted 32, and Dundee 28.
However, Aberdeen University has admitted no students with an HND, Abertay, in Dundee, has admitted one, Edinburgh eight students and Stirling 12 students.
While the figures are not necessarily a reflection on whether the institutions widen access effectively, NUS Scotland said all universities should make more use of the HND route.
Figures obtained by The Herald showed the three-year £1.8m Access to the Professions project will recruit just 29 extra lawyers per year from the 40% most deprived areas in Scotland. It will deliver just 23 more medical students, six architects, five vets and three dentists a year.