We previously described the critical incident (CI) monitoring in our ICU [1]. Our model is based on confidential reporting of critical incidents which could have reduced, or did reduce, the safety margin for the patient: the model regards errors or deviations not as human failures but as opportunities to improve the system (system approach). During a routine drug check, one of the staff nurses (with board certification) found erythromycin (Erythrocin® i.v.) (Fig. 1) in the place where surfactant (Survanta®) (Fig. 2) is usually stored (in a high performance refrigerator). The nurse realised that both drugs were manufactured and distributed by the same company (Abbott AG, Baar, Switzerland) and that the packaging was almost identical, a fact which could have accounted for the incorrect storage. She reported the observation on a critical incident monitoring sheet. All reports are analysed by the CI group (two nurses and one consultant) every 2 months. Since confusion of the two drugs, respectively for intravenous and intratracheal use, could be harmful [2], the CI group contacted the Swiss Intercantonal Office for the Control of Medicines (IKS) which, in turn, informed the manufacturer. Very shortly afterwards (4 months), the company changed the colour of the packaging for surfactant from red to blue (Fig. 3). This is an example of how our CI reporting system works: through a change in the system we endeavour to ensure a wider safety margin for the patient. This report highlights the importance of cooperation between health care providers (doctors, nurses), national drug control agencies and manufacturers. We encourage all prescribers of drugs to report observations likely to improve patient safety to their national medicine control agencies and drug manufacturers. As in our case, health care authorities and drug suppliers could play a constructive role in these efforts.