Giannis Kefalogiannis was born in Crete and studied medicine in Athens. Kefalogiannis was first elected to parliament in the 1950s. Kefalogiannis was also a member of the groups from across the political spectrum that resisted the Axis Occupation of Greece in the period 1941–1944, during World War II.
Kefalogiannis had been accused of telling two policemen to change their testimonies in court so that charges could be dropped against a suspected marijuana grower on Crete. Under Greek law, the charge of harboring a criminal also includes covering for a criminal.
The case took place in late 2003, when Kefalogiannis was still a deputy of the now-governing New Democracy party.
A Rethymno city court found him guilty of attempting to harbor a criminal and of instigating others to commit perjury, and handed him a one-year suspended prison sentence. He had said he would appeal the verdict.
Kefalogiannis has denied all the charges.He accused the prosecutor of attempting to blacken his name and claimed the trial was politically motivated. But Prime Minister Costas Karamanlis suspended him from his post until the appeal was heard.
Kefalogiannis was married to Eleni Verdinogianni and had 3 daughters.