Because over ninety percent of criminal convictions result from guilty pleas, perhaps the most important service criminal defense lawyers perform is advising their clients whether to plead guilty and on what terms. Nevertheless, virtually all jurisdictions hold that defense counsel need not discuss with their clients the collateral consequences of a conviction, such, as consecutive rather than concurrent sentencing, deportation, or even treatment as an aggravating circumstance in an ongoing capital prosecution. In this Article Professor Chin and Mr. Holmes argue that this "collateral consequences rule" is inconsistent with the Supreme Courts decision in Strickland v. Washington, which held that ineffective assistance of counsel consists Of performance below a minimum standard of competence and resulting prejudice. The ABA Standards for Criminal justice and other lawyering guidelines require defense lawyers to consider collateral consequences, and many of the cases espousing the collateral consequences rule rely on pre-Strickland case law. However, this Article recognizes that because guilty pleas are indispensable to the criminal justice system, judges justifiably hesitate to destabilize them. In order to prevent a mass exodus from prisons, it recommends modifying the rule to conform with existing Sixth Amendment doctrine.