In general, publications in this magazine deal with highly sophisticated semiconductor problems, while passive components are more in the background. However, if we look at electronics from a system-related point of view, we see that failure root causes-even those of semiconductor devices-are often related to a variety of capacitor failures, which deserve more focus and attention. This article reviews frequent-but often overlooked-reliability failure mechanisms of three main groups of capacitors: ceramic capacitors, foil capacitors, and electrolytic capacitors.