With the rising number of dengue patients, the economic burden to patients also increases particularly in the case when hospitalized. Severity has its own implication on dengue costs. We conducted a study to estimate the severity and costs of treatment among hospitalized dengue patients in Surat city, India. We used World Health Organization 2009 classification to classify the severity of dengue. We reviewed medical records and bills of dengue patients hospitalized in five tertiary care facilities (private [n = 2], semi-government [n = 2], and government [n = 1]) between April 2017 and March 2018. A resource utilization approach was used and cost of illness was estimated in US$ (inflation adjusted to 2018), from a quasi-societal perspective (excluding non-medical cost), for dengue hospitalization. With this approach, we estimated the aggregated cost as well as the cost associated with resources utilized for hospitalization. This helped us to compare the cost of treatment across different types of facilities and identify the main drivers of hospitalization costs. The resource utilization methodology would be useful for researchers to conduct similar studies in low- and middle-income country settings while generating evidence for policymakers on expenditure toward dengue hospitalization.