Prior research has demonstrated that patients admitted to the hospital on a weekend have a higher risk of mortality from conditions requiring emergency treatment and may experience a higher rate of preventable complications. These problems have been attributed to lower hospital staffing ratios on weekends. This article specifically evaluated the quality of care provided to patients hospitalized with acute myocardial infarction (AMI) and found that patients admitted on weekends were significantly less likely to undergo invasive treatments (such as cardiac catheterization or bypass surgery) within the first day of admission. This finding corroborates another recent study, which also found a lower rate of invasive procedure use among AMI patients admitted on the weekend, and also demonstrated increased mortality among those patients. Taken together, these results suggest that both increased staffing and incentives to perform weekend procedures may be needed to counteract the "weekend effect."