Unintended pregnancies and sexually transmitted diseases are some of the major reproductive health issues commonly encountered globally. As a developing country in South Asia, Sri Lanka has a prevalence rate of 23-46% of unplanned pregnancies. Two percent (2%) of government clinic attendees are detected with sexually transmitted diseases (STDs) and it is continually increasing among the young population. Poor knowledge, awareness and undesirable attitude towards contraception usage are some of the major factors associated with unintended pregnancies and transmission of STDs. Undergraduates are a vulnerable population to unintended pregnancies and sexually transmitted diseases. Therefore, this study was conducted with the objective of assessing the knowledge and attitudes towards the use of contraceptive methods among undergraduates of KIU. A descriptive cross-sectional study was conducted enrolling 304 undergraduates of 18 to 30 years of age using the simple random sampling method. Data were collected using a pre-tested self-administered questionnaire consisting of sociodemographic details and questions to assess participants’ knowledge and attitudes. The knowledge section of the questionnaire was marked out of 34 points, ones who obtained 0-12 marks were considered to have poor knowledge 13-24 as average knowledge and above 25 as good knowledge. The likert scale was used to assess the attitude section of the questionnaire. The results of the study revealed that the majority were females 62.5% (n=190) and 76.32% (n=232) of the study participants were from the age category of 23-27 years. Eighty-four percent (84%, n=255) of the study sample possessed a satisfactory level of knowledge in contraceptive methods and females showed a higher level of knowledge than males (p=0.002). Health science students had a higher level of knowledge than non-health science students (p=0.001). In conclusion, though the study population displays an overall positive attitude towards family planning methods, knowledge in this regard is average.