Background: Dengue is a mosquito-borne infectious disease of the tropical and subtropical countries which is rapidly becoming a global burden. It is caused by any of the four serotypes of dengue virus. Dengue disease presentation varies from mild fever with myalgia and fatigability to severe conditions of dengue haemorrhagic fever and shock syndrome. This study describes the clinical features, laboratory parameters and outcomes of the dengue fever patients during the monsoon season in a tertiary care hospital.Methods: This is retrospective, single centre study carried out at Yenepoya medical college and hospital (YMCH), Mangalore a coastal town in southern India. All patients who were adults (aged>16 years), positive for rapid (NS1 antigen) test or dengue IgM Elisa and admitted from 1-5-2019 to 31-9-2019 (monsoon season) were included in this study. Data was collected from the medical records of YMCH.Results: The male to female ratio of patients in this study was about 4:1. About 70.1% belonged to the age group between 16-35 years. The predominant symptoms on admission were fever, headache, myalgia, nausea and vomiting, abdominal pain, loose stools, bleeding manifestations and skin rashes. Average days of hospitalization are 5.88 days (SD 2.94). Thrombocytopenia leukopenia raised hematocrit and transaminases are the commonly observed laboratory findings. Ascites, pleural effusion, gall bladder wall edema, sepsis, bradycardia, hypotension, ARDS, and acute kidney injury are the complications observed during the illness. Mortality rate in this study is 1.9%.Conclusions: As seen in this study dengue fever is predominantly affecting the younger age group. The early confirmation of diagnosis, identifying the warning signs and prompt supportive management will help in preventing the further complications and in reducing the mortality. Increased public awareness and vector control measures are important factors to be taken into consideration in the prevention of dengue.