More than 300 flights at Germany's Duesseldorf and Cologne Bonn regional airports were grounded by a 24-hour strike by the Verdi trade union on Monday, the airports said.
The Duesseldorf airport on Monday said that 205 flights of a planned 330 were cancelled while 29 were diverted to other airports and seven were rescheduled for the next day.
Of Monday's usual 136 daily passenger flights scheduled for Cologne Bonn airport, 131 had been cancelled as of Sunday night.
Verdi announced the strike on Friday after it said collective bargaining efforts for public service workers and aviation security workers had failed to come closer to an agreement.
The airports, which service airlines including Lufthansa, Turkish Airlines and Aegean Airlines, were largely empty because passengers had been informed of the strike in time to change their plans.
The union brought air traffic to a standstill earlier this month with one-day strikes at seven major airports, including the Frankfurt and Munich hubs, affecting nearly 300,000 passengers.
Cities across the western state of North Rhine Westphalia, including Cologne, Leverkusen and Bonn, were also affected by public service worker strikes on Monday.