Lufthansa's back up plan is working, though about 100 flights began on Monday with short delays as of 7 am, Lufthansa spokesperson Klaus Walther told German broadcaster ZDF.
Trade union Verdi, which called the strikes in an ongoing wage dispute between Lufthansa and some 52,000 workers, said the airline could expect the first pinch of the walkout later in the afternoon.
But Walther encouraged Verdi to end the strike and return to the negotiating table, saying Lufthansa was ready to talk.
Verdi has asked for a 9.8 percent salary increase for the ground and cabin employees, but Lufthansa has offered a 6.7 percent increase to be implemented over a 21-month period, plus a one-time bonus payment.
The strikes began around 4 am and will include maintenance, catering, check-in and logistics personnel in Frankfurt, Cologne, Hamburg, Munich and Düsseldorf. Verdi announced the strike last week after union members voted overwhelmingly in favour of the action.
Lufthansa asks that passengers check their flights online or call hotline number 0800/850-60-70 for more information.