European regulators have come under fire for allowing Rome to use taxpayer money to save two small Italian banks, Veneto Banca and Banca Popolare di Vicenza.
The EU-approved operation could cost the Italian state up to 17 billion euros ($19 billion).
"In light of recent events, we need to look closely at whether our tools are sufficient, if they are effective and if we can do more," said Schaeuble, the eurozone's most influential finance minister, as he arrived for talks with his counterparts from the 19-country single currency bloc.
Schaeuble said he regretted the disparity between national rules and the far tougher European rules that only apply to eurozone's biggest lenders.
"We must have a discussion on how we can change that in the future," he said.
In the bailout, the two failing lenders' healthy assets are to be sold to Intesa Sanpaolo, Italy's strongest bank, for a symbolic price of one euro.
Critics say the bailouts run against the spirit of EU rules that are meant to protect taxpayers from being landed with the price of banking failures.
"We need a situation where everyone follows the rules," said Austrian Finance Minister Hans Joerg Schelling before the ministers were to review the rescue with EU officials.
Eurogroup head Jeroen Dijsselbloem said the eurozone would table fresh proposals on the EU's so-called banking union by the end of the year.
"There are huge problems (in Italy) and we need to make sure that these type of problems don't occur in the future," said Dijsselbloem, who is also Dutch finance minister.