Dengue is a viral infection transmitted to humans through the bite of an infected mosquito. Various clinical and laboratory parameters are used to predict the severity of this disease. Objective This study was aimed at comparing and analysing eight haematological parameters, including haemoglobin, haematocrit, platelet count, three platelet indices [mean platelet volume (MPV), plateletcrit (PCT), platelet distribution width (PDW)], total leucocyte and erythrocyte count, in the case of dengue seropositive, dengue seronegative but clinically suspected dengue and healthy controls. Methods We retrospectively analysed patient records from the Central Laboratory of Subharti Hospital, Meerut (UP). In this laboratory based-study, between October 2021 and January 2022, 300 subjects were examined including 200 hospitalised patients with probable dengue fever and 100 healthy subjects. Result The data was evaluated from 200 patients and 100 healthy controls (age between 6-70 years, mean 31 years). Quantitative analysis of patients and controls laboratory data revealed a significant difference in haemoglobin, packed cell volume (PCV), platelet count, and PDW (platelet distribution width) with p-values <0.05. Qualitative analysis of all-haematological parameters, was also statistically verified and had p value < 0.001. Conclusion In addition to platelet count, haemoglobin, PCV, and PDW are useful parameters to assess severity and recovery after dengue diagnosis.