This retrospective study was conducted to analyze clinical and laboratoristic parameters to individuate specific differences and facilitate differential diagnosis between Measles and Kawasaki Disease (KD) at first evaluation in a emergency room. We found similar clinical features as duration of fever and number of KD criteria (p >0.5) but significant differences in white blood cell count, neutrophils, CRP and LDH levels (p < 0.001). LDH value ≥ 800 mg/dl had sensibility of 89% and specificity of 90% for Measles while CRP ≥ 3 mg/dl had sensibility 89% and specificity of 85% for KD. The combined use of CRP, LDH and AST showed accuracy of 86.67%.