During and immediately after myocardial infarction (MI), many interrelated and complex processes manifest the body's attempt to minimize damage and compensate for lost cardiac function. Although these compensatory responses may provide some short-term restoration of function, their long-term consequences actually may increase morbidity and mortality. Several agents have established roles in the treatment of these patients, whereas others, including the angiotensin-converting enzyme (ACE) inhibitors, have yet to be investigated thoroughly. Results of two trials investigating the role of ACE inhibition after MI seem to provide sufficient data to warrant the use of these drugs in certain patient populations. These results are promising, but further investigation is necessary to answer key questions arising from these trials.