Problem detection is a critical component in nursing, such that superior detection could lead to quicker intervention, even if the nature of the problem is not yet clear. A critical problem intensive care nurses typically engage in is detecting the threat of an impending hospital-acquired infection. The purpose of this study was to investigate the effects of the presence of risk factors, expertise, and time pressure on problem detection. The results suggested that time pressure seemed to have a detrimental effect on problem detection, and nurses benefitted from the presence of more risk factors. When not under time pressure, nurses were more sensitive in their problem detection judgments, and only needed one risk factor to trigger problem detection. Experienced nurses were more sensitive to the type of infection at detection, and were more likely to identify the problem correctly after information had been accumulated. These results suggest that problem detection was differentially affected by risk factors based on the presence or absence of time pressure. In addition, experienced nurses took a different approach to problem detection when compared to novices. Finally, problem detection and problem identification can in some situations occur simultaneously, but are distinct processes.