"Investment in new aircraft strengthens the competitiveness of airlines in the Group. Besides greater fuel efficiency, all the models on order will help lower operating costs as well as noise levels and emissions," Lufthansa said in a statement.
The Airbus planes are for passenger use while the Boeings 777 is "the most modern freighter of its size," the company said.
Last week Lufthansa reported a return to profit as it bounced back from a net loss of 34 million euros in 2009.
This year could be tougher, however, because high oil prices will cut airline industry profits by nearly half despite the growth in air travel with the recovery, according to the International Air Transport Association.
In its latest order, the German carrier booked 25 A320neo and five A321neo aircraft destined for continental European traffic.
The deliveries are scheduled to begin in 2016.
"The aircraft come with improved aerodynamics and new engines. They burn around 15 per cent less fuel than today's comparable models," Lufthansa said.
Noise emissions will also be 10-15 decibels below current, the company added.
The Boeing 777 freighters are slated to join the fleet from 2013.
They will be utilised "to seize growth opportunities fuelled by rising demand," the airline said.