Anecdotal evidence suggests that anxiety and lack of confidence in managing acutely ill patients adversely affects performance. We evaluated the impact of attending an ALERT™ course on the confidence levels and attitudes of healthcare staff in relation to the recognition and management of acutely ill patients. A questionnaire, which examined knowledge, experience, confidence and teamwork, was distributed to participants prior to commencing an ALERT™ course. One hundred and thirty-one respondents agreed to participate in a follow-up questionnaire 6 weeks after completing the course. Respondents reported significantly more knowledge (pre 5.47±1.69, post 7.37±1.22; p<0.01) in recognising a critically ill patient after attending an ALERT™ course. Mean scores for respondents’ confidence in their ability to recognise a critically ill patient (pre 6.04; post 7.71; t=11.74; p<0.01), keep such a patient alive (pre 5.70; post 7.30; t=10.01; p<0.01) and remember all the life-saving measures (pre 5.60; post 7.32; t=11.71; p<0.01) were increased. Fewer respondents were very worried about being responsible for a critically ill patient (pre 13; post 2; χ 2 =8.55; p<0.003). There was a significant increase in the number of respondents indicating that they would use a system of assessment for acute illness (pre 23; post 37; χ 2 =4.25; p=0.035). More staff said that they would approach a registrar or a consultant for help (χ 2 =3.29, n=131, p<0.05; χ 2 =7.51, n=131, p<0.01). There was a significant improvement in attendees’ confidence in working in an interdisciplinary team when caring for critically ill patients (pre 40.66; post 42.91; t=2.32; p=0.05). We conclude that attending an ALERT™ course has beneficial effects on the confidence levels and attitudes of healthcare staff in relation to the recognition and management of acutely ill patients.