Objective: The purpose of this study was to identify whether there is an increase in type I interferon and proinflammatory cytokine levels in the cerebrospinal fluid of newborns with rotavirus-associated leukoencephalopathy. Methods: Levels of type I interferons (interferon-alpha and interferon-beta) and proinflammatory cytokines (interleukin-6 and interferon-gamma) were measured in the cerebrospinal fluid of 23 newborns with rotavirus-associated leukoencephalopathy (patient group) and 39 infants under 90 days-of-age (control group). Results: Cerebrospinal fluid pleocytosis was not observed in either group. Cerebrospinal fluid interleukin-6 levels were significantly higher in the patient group (7.02 +/- 5.88 pg/mL) than in the control group (1.14 +/- 1.90 pg/mL) (p <.0001). The mean cerebrospinal fluid interferon-gamma levels of the patient group (24.43 +/- 40.16 pg/mL) were also significantly higher than those of the controls group (0.0 +/- 0.0 pg/mL) (p <.0001). Cerebrospinal fluid interferon-alpha was not detected in any patient (0%) from the patient group, but was detected in four (10.3%) of the controls. Interferon-beta was detected in only two patients (8.7%) from the patient group and in one (2.6%) of the controls. Cerebrospinal fluid interleukin-6 levels correlated positively with the extent of white matter lesions on diffusion-weighted magnetic resonance imaging (r = 0.607, p=.002). Conclusions: Significant increases in proinflammatory cytokine levels accompanied by very low detection rates of type I interferon in cerebrospinal fluid indicate that rotavirus-associated leukoencephalopathy in newborns can be correlated with central nervous system inflammatory processes without direct virus invasion into the central nervous system. (C) 2017 The Japanese Society of Child Neurology.