The industrial action runs between 6am and 12pm (0500 GMT to 1100 GMT) and has forced the cancellation of more than 40 flights to and from Frankfurt, continental Europe's biggest hub, and Berlin-Tegel airport, according to Lufthansa's website.
A spokeswoman for the airline refused to say exactly how many flights had been cancelled but flights to London, Zurich, Milan and Prague were cancelled in a 30-minute stretch from 0700 GMT, according to the Frankfurt Airport website.
Lufthansa said it was trying to limit the impact on long-haul flights but warned that delays could also be expected to these services.
Staff stopped work in a bid to ratchet up the pressure on employers during wage negotiations. The flight attendants are demanding a 15 per cent pay rise. The airline has offered 10 per cent.
Talks between the union representatives and Lufthansa broke up two weeks ago without agreement.
The UFO trade union which called the strikes represents 8,000 of the 16,000 flight attendants at Lufthansa.
During last Friday's action, 44 flights were cancelled during a three-hour warning strike. According to UFO, 400 flights were delayed.