In a regional economic study published on Monday, the Paris-based international organisation claimed that more needed to be done to protect the EU's banking system from future shocks and to tighten the European Growth and Stability Pact.
It also warned that financial support to stricken countries such as Greece should be withdrawn if restructuring conditions are not met.
"Few countries have developed a comprehensive approach to deal with weaknesses in the banking system," the report said. "Further recapitalisation of banks could be necessary.
"Stronger regulations are needed to improve financial stability. Effective microprudential regulation is the first line of defence.
"This should be upgraded by implementing the Basel III capital accord... and a range of related measures. Some consideration should be given to an accelerated phasing-in."
Presented by OECD Deputy-Secretary General and chief economist Pier Carlo Padoan in Brussels today, the study calls for EU stress tests to become "a regular exercise" and for an overhaul of the European Growth and Stability Pact to include significant penalties for misbehaving countries.
"Sanctions should range from intrusive surveillance and warnings by the Council to financial sanctions. Monetary penalties should include the requirement that funds be posted to an interest bearing account until corrective policies have been implemented."
The OECD, which has 33 member governments, said it supported a "credible mechanism" for fiscal crisis management, but warned that financial support for countries facing liquidity crises, such as Greece, should be withdrawn if strict conditions attached are not fulfilled.
"The framework should be prepared to deal with this eventuality," it said. "Sovereign risk should be fully reflected in financial regulations."