Pegloticase-associated adverse events reported to the Food and Drug Administration Adverse Event Reporting System (FAERS) database in the United States were evaluated. Retrospective data-mining analysis of FAERS case reports listing Krystexxa or pegloticase as the suspect drug and specific adverse events (cardiovascular events, infusion-related reactions, gout flares, and anaphylaxis) was conducted from the drug's approval date (September 14, 2010) through August 27, 2012. Initial and follow-up reports with the same primary linked identification number were identified as unique to each patient case. When multiple reports for the same patient were identified with a common case number, the report with the most recent date was used to eliminate duplicate reports. Bayesian confidence propagation neural network methodology was used to identify signals of drug-associated adverse events. A potential signal for drug–adverse event reports is generated when the lower limit of the 95% two-sided confidence interval of the information component is greater than 0. A total of 118 unique cases of adverse events involving pegloticase in the United States were identified during the study period. Fourteen reports were related to pegloticase-associated cardiovascular events, and 35 were related to pegloticase-associated infusion-related reactions. Twenty-six reports were related to pegloticase-associated gout, and 11 were reports of pegloticase-associated anaphylaxis. Bayesian statistics identified potential signals for all pegloticase-associated adverse events (cardiovascular events, infusion reactions, gout flares, and anaphylaxis). Analysis of pegloticase-associated adverse events submitted to the FAERS database found that cardiovascular events, infusion-related reactions, gout flares, and anaphylaxis occurred more frequently than was statistically expected.