To the Editor: Interleukin-6 (IL-6) may be associated with the generation of anti platelet and anti endothelial autoantibody, coagulation defects leading to bleeding and plasma leakage in dengue infection [1, 2]. This study included 60 children aged 6 mo-18 y, categorized into non-severe dengue (NSD) and severe dengue (SD) according to WHO 2009 Dengue Severity Criteria to assess whether IL-6 levels can predict severity of dengue fever. The mean IL-6 levels were assessed on 1st and 4th day of admission by using enzyme-linked immunosorbent assay kits from Krishgen Biosystems. Out of 60 patients, 15 (25%) belonged to SD on day 1 of admission, 10 (16.67%) belonged to SD on day 4 of admission and 6 (10%) patients expired within 4 d of admission. IL-6 levels of 616.1680 ± 449.0418 pg/ml (Mean ± Standard Deviation) on day 1 of admission and 747.2799 ± 558.9062 pg/ml (Mean ± Standard Deviation) on day 4 of admission corresponded to SD, p value being 0.0176 and 0.0025 respectively. Sehrawat et al., also found a significant higher level of IL-6 among the patients with SD [3]. Also, IL-6 levels on day 1 of admission of >265.4565 pg/ml is observed in predicting mortality with the sensitivity of 67.30%, specificity of 75.00%, negative predictive value (NPV) of 26.09% and positive predictive value (PPV) of 94.59% and on day 4 of admission, IL-6 levels of >495.7575 pg/ml is observed in predicting mortality with the sensitivity of 84.62%, specificity of 100.00%, NPV of 20.00% and PPV of 100.00%. Suharti et al., also found increased IL-6 in dengue shock syndrome (DSS) non-survivors [4]. Hence, it can be concluded that IL-6 levels at presentation can predict severity of dengue and its clinical outcome with high diagnostic accuracy. Thus, IL-6 levels of >450 pg/ml on day 4 of admission should raise high index of suspicion for poor clinical outcome (mortality) in dengue fever.