Background: Dengue fever continues to pose significant challenges in public health, particularly within developing countries where it remains endemic. The ability to distinguish dengue infection from other febrile illnesses and assess its severity is crucial. The analysis of hematological parameters and inflammatory biomarkers, particularly C-reactive protein (CRP), offers valuable insights into the disease's progression. Objective: This study aimed to delineate the severity of dengue fever through detailed evaluation of complete blood count (CBC) and CRP levels, and to establish a correlation between these markers and the clinical severity of the infection. Methods: In this retrospective cross-sectional study, 135 suspected dengue fever patients from the City University of Science and Information Technology Peshawar were screened using the immune-chromatographic technique (ICT). Among them, 50 individuals (37%) tested positive for dengue. Both CBC and CRP levels were measured, with data analyzed using the statistical package SPSS version 22.0. The study spanned demographic data collection, gender and age distribution assessment, and detailed analysis of hematological parameters alongside CRP to predict disease severity. Results: Among the confirmed cases, the gender ratio skewed towards males (60%) compared to females (40%), with the most affected age group being 15-25 years (34%). Leukopenia was identified in 58% of patients with a mean WBC count of 2.62 × 10^9/L, neutrophilia in 66% with a mean neutrophil percentage of 80.15%, and lymphopenia in 56% with a mean lymphocyte percentage of 10.28%. Thrombocytopenia was observed in 76% of the cases. Elevated CRP levels were found in 88% of patients, with a mean CRP value of 23.10, indicating a strong predictive correlation with disease severity (p-value= 0.001). Conclusion: The study reaffirms the role of CBC and CRP levels in the clinical assessment of dengue fever, with both markers being indicative of infection severity. These findings can aid in the early detection and management of dengue fever, potentially guiding decisions regarding the necessity of hospitalization.