Introduction: Dengue fever is one of the most common vectorborne infections worldwide and is now endemic in Kerala. Knowledge about changing clinical presentation of dengue fever is important for timely diagnosis and appropriate management. Aim: To document changing trends in clinical presentation and course of illness among patients admitted with dengue fever in Kerala, India. Materials and Methods: This hospital-based, retrospective, observational study was conducted at Government Medical College and Hospital, Kannur, Kerala, India, from September 2021 to June 2022. The patients with dengue fever, presented in seasonal epidemic of the year 2019 was compared to similar patients presented during the year 2014. Data regarding clinical presentation, duration of hospital stay, complications and haematological parameters of the study population was collected using prevalidated questionnaire. Descriptive data were expressed in frequency, percentage, mean and standard deviation. Continuous and discrete variables were compared by Welch's t-test, whereas categorical variables were compared using Pearson's Chi-square test. Results: Out of the total 184 patients studied, 91 were from 2014 and 93 from 2019. The major presenting complaints were fever, body aches, headache, nausea and vomiting, arthralgia, and retroorbital pain incidence of which were similar in both the study years. Patients admitted in 2019 have shorter duration of fever (5.78 vs 6.79 days), earlier onset of severe thrombocytopaenia (6.62 vs 7.27 days) and delayed onset of complications (5.56 vs 3.6 days) compared to those admitted in 2014. They also had higher incidence of thrombocytopaenia (70.97% vs 54.94%) and complications (49.46% vs 14.29%) during the course of their illness. Conclusion: The study indicates towards a significant shift in clinical presentation of dengue fever in Kerala which may influence the admission and monitoring protocol of dengue fever patients in the years to come. [ABSTRACT FROM AUTHOR]