Catheter-associated urinary tract infection (CAUTI) is one of the most common nosocomial infections in intensive care units (ICUs). Previously, varied diagnostic criteria for CAUTI were published, which were mainly based on a combination of clinical and microbiological parameters. However, the diagnosis of symptomatic CAUTI might be particularly difficult in critically ill patients because typical symptoms of urinary tract infection such as urgent or frequent urination, were often masked by an impaired level of consciousness. Moreover, reliable diagnostic tests for distinguishing colonization from infection were not available yet. However, patients who are complicated with unaccountable fever and exposed to high risk factors of CAUTI (i.e.CAUTI was highly suspected) need to be seriously concerned in ICU owing to a deleterious outcome. IDSA-2009 and NHSN/CDC-2015 guidelines for diagnosis of CAUTI are likely more suitable for ICU patients. However, at present, validity of diagnostic criteria for CAUTI remains a big problem in our routine practices in ICU.