In this qualitative study using observation and interviews, 10 anaesthetists from five Departments of Anaesthesia in the North-West region of England were enlisted to participate in the design of an online system to allow the sharing of critical incidents. Respondents perceived that existing schemes had differing and sometimes conflicting aims. Reporting was used for reasons other than simply logging incidents in the interests of promoting patient safety. No existing scheme allowed the lessons learned from incidents to be shared between members of the professional group from which they arose. Using participants' suggestions, we designed a simple, secure, anonymous system favouring free-text description, intended to enable the on-line sharing and discussion of selected incidents. Seven incidents were posted during the 6-month pilot period. The practitioners in our study valued the opportunity to share and discuss educational incidents ‘horizontally’ within their community of practice. We suggest that large-scale reporting systems either incorporate such a function or allow other systems that permit such sharing to co-exist.