Lecturers are being balloted for industrial action in response to a below-inflation pay offer.
The Educational Institute of Scotland (EIS) rejected a 1% offer from higher education employers.
Larry Flanagan, EIS general secretary, said: "Lecturers in Scottish higher education institutions have endured pay awards of less than the rate of inflation for each of the past three years and are not prepared to accept a fourth year of real-terms pay decline.
"The EIS estimates that higher education lecturers have suffered real-terms pay cuts of over 12%, or around £5,000, during the past three years, and this is completely unacceptable."
Staff are "absolutely essential" to the success of Scotland's colleges and universities, and they should be "fairly remunerated", he said.
The EIS said it will work with other trade unions in a co-ordinated campaign on lecturers' pay, which is negotiated at a UK level.
The ballot runs until October 10. Industrial action would start on October 23 if members back the EIS plan.
A Scottish Government spokeswoman said: "The Scottish Government has invested significant funding in our universities and colleges, and we appreciate the hard work and dedication of staff in the education sector.
"As independent bodies, pay is a matter for institutions, staff and the appropriate unions, and we hope a solution can be found which avoids any disruption to students learning."