Operating profit for the year was 212 million francs, down from 306 million in 2011, while total income rose two percent to just over five billion francs.
The company, a subsidiary of Germany's Lufthansa group, noted that operating profit in the fourth quarter of 27 million francs marked an improvement over the 18 million francs earned in the same period a year earlier, although revenues of 1.2 billion francs were flat.
"We continue to face strong business headwinds," Swiss CEO Harry Hohmeister said in a statement.
"But we did take a number of actions in the course of last year to improve our earnings performance."
While releasing financial results, Swiss announced that it would buy Boeing planes for the first time, ordering six long-range 777 jetliners to replace its Airbus A340s.
Swiss said it would pay 1.5 billion francs ($1.6 billion) for the aircraft.
"The decision to opt for Boeing's successful 777 was taken after extensive evaluations," the company said.
The replacements will begin in 2016 with the new twinjets to be used on Swiss's "ultralong" routes to destinations such as San Francisco, Los Angeles, Sao Paulo, Bangkok, Hong Kong, Shanghai, Beijing, Johannesburg and Singapore.
With more than 330 seats, the Boeing 777-300ER offers fuel and carbon dioxide savings of 23 percent over the A340, Swiss said.
The company also said it set a new aviation record for Switzerland by carrying 15.8 million passengers in 2012, 3.3 percent more than in 2011