New figures show that student numbers have fallen from 257,913 in 2011/12 to 238,805 in 2012/13 - a decline of more than 7%. There were 379,233 college students in 2007/08.
The number of college staff has also fallen sharply with 10,622 in 2012/13 compared to 12,892 in 2008/09 - a fall of 17%.
The decline in student numbers follows the Scottish Government's decision to prioritise full-time courses for younger students to cut youth unemployment.
As a result, the number of part-time, weekend and evening courses has been reduced, with funding withdrawn for many.
Michael Russell, the Education Secretary, highlighted the fact the overall amount of learning offered by colleges has remained stable with a rise in full-time courses - although the number of full-time students has declined slightly this year.
He said: "The figures show the Scottish Government's reform of post-16 education is working for colleges.
"As well as fulfilling our commitment to 116,000 funded full-time equivalent places, the sector is delivering for individual students, even in the face of restrictions placed on the Scottish budget by Westminster."
However, opposition politicians attacked the SNP's record on further education after a significant re-organisation and cuts of millions of pounds to teaching budgets. Scottish Conservative education spokeswoman Mary Scanlon said: "These damning figures show just how committed the SNP is to college education.
"The decision to slash the college budget was wrong and the impact of it can be seen in the numbers of those winning a place to study."
Kezia Dugdale, Scottish Labour's education spokeswoman, called the decline a "disgrace".
"The raid on colleges has seen part-time courses slashed, teacher numbers cut and female admissions plummet.
"The result of SNP choices is thousands of lost opportunities for those whose only chance to access further study would be college. It's a disgrace and shows a complete lack of leadership and vision from the Scottish Government."
Gordon Maloney, president of NUS Scotland, called for protection for part-time courses.
And Larry Flanagan, general secretary of the Educational Institute of Scotland, said the decline in staff had "serious implications" for course provision.