Although it is well established that health care professionals use tacit and codified knowledge to provide front-line care, less is known about how these two forms of knowledge can be combined to support improvement related to patient safety. Patient safety interventions involving the codification of knowledge were co-designed by university and hospital-based staff in two English National Health Service (NHS) hospitals to support the governance of medication safety and mortality and morbidity (M&M) meetings. At hospital A, a structured mortality review process was introduced into three clinical specialities from January to December 2010. A qualitative approach of observing M&M meetings (n = 30) and conducting interviews (n = 40) was used to examine the impact on meetings and on front-line clinicians and hospital managers. At hospital B, a medication safety 'scorecard' was administered on a general medicine and elderly care ward from September to November 2011. Weekly feedback meetings were observed (n = 18) and interviews with front-line staff conducted (n = 10) to examine how knowledge codification influenced behaviour. Codification was shown to support learning related to patient safety at the micro (front-line service) level by structuring the sharing of tacit knowledge, but the presence of professional and managerial boundaries at the organisational level affected the codification initiatives' implementation. The findings suggest that codifying knowledge to support improvement presents distinct challenges at the group and organisational level; translating knowledge across these levels is contingent on the presence of enabling organisational factors, including the alignment of learning from clinical practice with its governance.