Erdoğan's comments, in a speech on Sunday (11 November), follow an upsurge in Kurdish militant violence which has raised pressure on the government to act over a conflict that has killed more than 40,000 people since it began 28 years ago.
"In the face of deaths, murders, if necessary the death penalty should be brought back to the table [for discussion]," Erdoğan told a crowd.
Turkey abolished the death penalty in peacetime in 2002 under reforms aimed at EU membership. It was abolished totally in 2004, two years after Erdoğan's AK Party came to power.
Abolition of the death penalty is a pre-condition for EU entry. But Turkey's progress towards EU membership has ground to a halt in recent years amid opposition from France and Germany and Erdoğan has become increasingly dismissive of the bloc, focusing instead on Turkey's role as a regional power.
A spokesman for EU Enlargement Commissioner Štefan Füle said global abolition of the death penalty was one of the main objectives of the EU's human rights policy.
"Therefore, when the Commission monitors compliance by candidate and potential candidate countries with the political criteria, it looks at the legal provisions on the death penalty," the spokesman said.
Political commentators accused Erdoğan of populism ahead of the 2014 presidential election in which he is widely expected to run.
When capital punishment was abolished, separatist militant Abdullah Ocalan was on death row after being sentenced in 1999 as leader of the Kurdistan Workers Party (PKK), designated a terrorist group by Turkey, the United States and European Union. European pressure on Ankara not to execute Ocalan played a major role in the reform.
Tensions are running high in Turkey over a hunger strike by hundreds of Kurdish militants demanding greater rights and improved prison conditions for Ocalan, who has not seen his lawyers for 15 months.
The last time a prisoner was executed in Turkey was in 1984. Prime Minister Adnan Menderes was executed along with two cabinet ministers in 1961, a year after an army takeover.
Erdoğan pointed to the United States, Russia, China and Japan as countries where capital punishment is implemented, saying Turkey must review the situation. He suggested families of murder victims should have a say in the fate of killers.