Introduction: Obesity is of much concern to millions of people on over the world not only as it is pasted a lot of Salk but it has also begin to be ranked as a serious risk comparable to certain disease. Obesity result well much font occurring the body.Objectives:- To assess the knowledge regarding complication of obesity among adults.To assess the attitude towards complications of obesity among young adults.To find out the association between the knowledge of obesity complication with their socio demographicvariables.Material and methods: The present community based cross- sectional descriptive study was conducted in Narayana Medical College Hospital, Nellore, Andhra Pradesh state(India). The study sample included 60 the young adults between 19-40 years selected by convenience sampling technique.Results and Discussion:- The findings of the study revealed that out of 60 young adults 32(53.3%) of were had inadequate knowledge, 13(23.3%) of young adult had average knowledge and 15(25%) of youngadults were had inadequate knowledge on complications of obesity and out of 60 young adults 37 (61.1 %) adults were needs to improves their attitude had positive attitude ,19 (31.6%) of adults were naturalattitude in their attitude and 4(6.66%) adults were had in negative attitude. Conclusion: the majority of obesity complication of young adults has average knowledge regarding obesity complication at Narayana Medical College Hospital Nellore. It indicates that there is a need for creating awareness among young adults.