Reporting systems, morbidity and mortality conferences, and case review all serve as mechanisms to learn about adverse events and identify opportunities for improvement. However, many of these forums rely on voluntary measures to bring issues to the forefront, leaving many “water cooler” conversations as a lost opportunity for organizational learning. This ethnographic study explores how informal knowledge sharing, the proverbial water cooler conversation, takes place in a staff lounge, a storeroom, and an operating room corridor. The authors found rich information sharing in this context, perhaps fueled by the trusting and mutually desired setting for the exchanges. They advocate for greater attention to capturing and fostering these communications as a potentially important source of hidden advancement in patient safety knowledge and a positive safety culture.