['The objective of this study is to assess the prognostic usefulness of the Multinational Association of Supportive Care in Cancer (MASCC) risk score in association with the value of C-reactive protein (CRP) to identify high-risk patients with febrile neutropenia and hematologic neoplasms.', 'A retrospective cohort study in which the MASCC score and the CRP values were used to assess the mortality risk at 30 days among patients with febrile neutropenia and hematologic malignancies was performed.', 'Two hundred thiry-seven patients with febrile neutropenia were analyzed; the mortality rate within 30 days was 9 %. High-risk patients according to the MASCC score were significantly more likely to experience adverse outcomes, such as being transferred to the intensive care unit (RR 3.55; CI 95 % 2.73-6.62, p\u2009<\u20090.001) and death (RR 2.21; CI 95 % 1.74-2.79, p\u2009<\u20090.001). Multivariate analysis showed a strong association between the high-risk group identified by the MASCC score (HR 3.0; CI 95 % 1.12-13.54, p\u2009=\u20090.032) and the mean levels of CRP (HR 17; CI 95 % 2.21-136.48, p\u2009=\u20090.007) and survival. The survival rate within 30 days was 100 % for the patients with a low-risk MASCC score and a mean CRP less than 15 mg/dL. This rate was only 64 % for high-risk patients with a mean CRP greater than 15 mg/dL.'] Do c-reactive protein and the MASCC risk index identify high-risk patients with febrile neutropenia and hematologic neoplasms?