Members of the Educational Institute of Scotland (EIS) decided to walk out in a dispute over terms and conditions at Edinburgh College.
On the eve of the strike, the college had offered to raise the previous maximum salary offer of £34,700 to around £36,000 over a two-year period.
A college spokesman said: "We hoped they would suspend the strike while they looked at the details."
EIS general secretary Larry Flanagan said: "Edinburgh College lecturers are determined to continue their programme of industrial action until management agree to rethink their offer on terms and conditions.
"Lecturers do not want to strike, but feel that they simply have to take this action in protest at the damaging changes to conditions of service that college management has proposed.
"There has been very strong support for the strike from lecturers, and numerous messages of support from students and others who appreciate the important work that lecturers in the college carry out and the benefits this brings for the entire community."
The college says it is seeking to "harmonise" contracts for teaching staff, making them "equitable, fair and affordable" and bringing all teaching staff together on one set of terms and conditions and the same pay scale.
The revised offer would also introduce a maximum number of teaching hours at 24 per week.
A limit on weekly teaching hours is one of the reassurances the union has been asking for. The new offer retains the 800-hour annual maximum teaching hours that was part of the original offer, which was already significantly less than all three legacy colleges.
Edinburgh College principal Mandy Exley said: "We have listened to staff, considered what they need very carefully and come back with solutions to their issues. This offer demonstrates that we're committed to preventing any more disruption to students and doing what is most important - ensuring their education needs are fully met and that we support our staff in a fair, affordable way."
Ian McKay, chairman of the college's board of management, said: "We're very disappointed the EIS officials have not suspended this week's strike action. They've been given a fair offer that they can now put to their members and striking this week will only harm the students.
"The college has done what we can to prevent this happening, so the decision now lies with the EIS and its members."