Ultrasound-nucleated cavitation of microbubbles can induce a variety of therapeutic bioeffects. As a result, many studies have been performed that passively monitor cavitation emissions as a proxy for understanding how microbubble cavitation induces bioeffects. More recently, monitoring of cavitation emissions is being used to guide the therapeutic ultrasound insonation parameters. The vast majority of these studies have used fixed-focus single-element transducers, which do not provide both broad spatial specificity and spatial sensitivity. However, in the past decade array-based reception of cavitation emissions has allowed passive acoustic maps (alternatively referred to as passive cavitation images) to be created by beamforming the passively received emissions. Basic algorithms and implementations have now been used in a number of therapeutic ultrasound applications, including HIFU thermal ablation, drug delivery, blood-brain barrier disruption, and mechanical ablation (i.e., histotripsy). The concept behind passive acoustic mapping will be introduced and used as a jumping stone to highlight areas of potential future improvement. These areas include the development of calibrated images, improving image resolution, increasing frame-rates, properly assessing spectral content, and determining how to use the temporal-spatial information for treatment guidance.