In 2007/08, there were almost 182,000 women studying part-time courses but that has fallen each year since then to almost 102,000 in 2011/12.
Over the same period, the number of women on full-time courses has increased from just over 37,000 to almost 43,000.
The Scottish Government said the fall in part-time and increase in full-time numbers is the result of a “re-focusing on delivering courses that focus on employability” and reflects “a move away from funding very short programmes of study (under 10 hours) and leisure programmes”.
Calculating female headcount based on full-time equivalents shows there were over 69,000 full-time equivalent places in 2007/08, fluctuating over the years to almost 69,000 in 2011/12.
The Government said this provides “a better measure of the volume of learning” over the period.
But the Tories said the reduction in part-time opportunities shows a “disregard for courses favoured by many mothers and women attempting to balance studying and part-time work”.
The party’s education spokeswoman Mary Scanlon said: “The SNP has made great play of targeting full-time courses but that’s no use for those who can’t put that kind of time commitment into college.
“This approach discriminates against those who want to change career but cannot afford to revert to being a full-time student.
“As we can see from these figures, it certainly discriminates against women who want to boost their skills, but have other commitments in life such as young children.
“Scotland has a proud history of college education and much of that is down to the flexibility offered across the board.
“The SNP is hammering that flexibility, as well as cutting funding and staff numbers.
“Colleges play an important role in reducing inequality - so many turn to these part-time courses to boost their skills and increase the money they earn for themselves and their families.
“They are a key route to allowing people from all backgrounds to better themselves.
“It’s time the Scottish Government started listening to students, lecturers and business leaders, who have all been extremely critical of its recent approach to college education.”
A Scottish Government spokesman said: “Colleges are rightly focusing on delivering full-time courses that deliver the skills and qualifications people need to get a job and develop their careers.
“Women account for the majority of full-time students and all students are being supported with record levels of financial support - over £102 million this academic year in college bursaries, childcare and discretionary funds, including additional money for women returning to education.
“The prioritisation of full-time courses has been endorsed by the most recent labour market statistics that showed we now have a record high level of women in employment in Scotland, with 61,000 more women in the workplace compared to the previous time last year.”