Alert fatigue is an increasingly recognized patient safety concern. This retrospective study examined the association between habit and dismissal of indwelling catheter alerts among physicians at one hospital in Singapore. Findings indicate that physicians dismissed 92% of all alerts and that 73% of alerts were dismissed in 3 seconds or less. The study also concluded that a physician’s prior dismissal of alerts increases the likelihood of dismissing future alerts (habitual dismissal), raising concerns that physicians may be missing important alerts.