The 14 officers were found guilty by a jury after what was Malaga province's longest-ever trial, lasting one month and a day.
The officers now face fines and possible suspension from duty.
A Chinese citizen was also found guilty in the case while three other Civil Guard officers were cleared of all charges.
Investigations into the case began in 2005 after claims that officers at Malaga airport were demanding money from departing passengers in exchange for confiscating 'prohibited' items — generally foodstuffs.
Evidence used in court included video footage of officers searching passengers bags. When suspect or banned items were found, passengers handed over cash to be allowed to take those items across the border.
In some cases, travellers were told items were banned although this was not actually the case.
Malaga airport is Spain's fourth busiest. Some 12.5 million passengers passed through its doors in 2012.