C-reactive protein (CRP) is an acute phase reactant of inflammation. We evaluated the clinical value of serial measurement of CRP in neutropenic patients. CRP was shown to be useful to monitor the response to therapy for febrile episodes in neutropenia. However, we failed to show statistically significant differences in CRP levels between febrile episodes with or without clinically documented infection (p= 0.10) and with or without bacteremia (p = 0.55). Also, we could not predict febrile episodes within three days by the elevation of CRP value. The area under receiver-operating characteristic curve depicting the relationship between CRP levels and forthcoming febrile episodes was only 0.60. In conclusion, serial measurement of CRP was considered to be not useful to predict fever within three days, or to differentiate the types of infection.