With increasing emphasis on patient safety/quality improvement, health care systems are mirroring industry in the implementation of root cause analysis (RCA) for the identification and mitigation of errors. RCA uses a team approach with emphasis on the system, as opposed to the individual, to accrue empirical data on what happened and why. While many otolaryngologists have a broad understanding of RCA, practical experience is often lacking. Part II of this patient safety/quality improvement primer investigates the manner in which RCA is utilized in the prevention of medical errors. Attention is given to identifying system errors, recording adverse events, and determining which events warrant RCA. The primer outlines steps necessary to conduct an effective RCA, with emphasis placed on actions that arise from the RCA process through the root cause analysis and action (or RCA2) rubric. In addition, the article provides strategies for the implementation of RCA into clinical practice and medical education.