Background: Health seeking behavior is an important decision in health care management and it becomes more relevant among underprivileged populations like urban slums. The objectives of the study was to find out the morbidity pattern, health care seeking behaviours , the morbidity pattern its determinants among urban slum dwellers in Chennai.Methods: This descriptive cross sectional study was conducted among 400 respondents of Nallakuppam slum in Chennai by systematic random sampling method from October 2017 to October 2019. A semi structured schedule was used to collect information among them after their valid informed consent. Descriptive statistics such as frequency and percentage were used. Chi square test was used to assess the association between factors.Results: Almost half of the study participants (53.50%) were female and 30.50% have completed high school education. Hindu was the major religion practiced and most of them belonged to lower middle socio economic class. Though majority of the study population suffered from communicable diseases like ARI and fever which might be due to overcrowding in that area, treatment seeking behavior was found to be good among the study participant suffering from non-communicable disease like DM, HTN and CHD, which showed that the type of disease played an vital role in seeking treatment among the study participants.Conclusions: Though the study participants had different choice in health care such as government, private or some time both facilities for treating their illness, trust on the health care provider played an important role in availing services from particular health care facilities.