The College of North West London has been brought to a standstill in a row over pay.
Members of University and College Union have been out in force at picket lines at the three college sites hit by the action.
The college has refused to honour a pay agreed more than four years ago which should have left a mid-ranking further education lecturer earning £4,511 more a year.
Eight other colleges across the UK are also taking part in the industrial action.
The union has described the failure of those colleges still to honour the deal as one of the longest IOUs from management to staff in the history of industrial relations.
Sally Hunt, UCU general secretary, said: "The college only has itself to blame for today's disruption. The staff are not greedy; they are merely asking for the money they should have been paid four years ago.
"It is the intransigence of the "IOU colleges" that has pushed members' patience too far and forced them into industrial action.
"Nobody involved with any of the colleges wants to see industrial action and once we ask the colleges to now sit down with us and discuss ways to resolve the issue and avoid any further unnecessary disruption.
"Flexible agreements have been agreed at a host of other colleges with serious financial difficulties to implement the deal."