Aim of this paper to highlight the impact of online advertisement on consumer buying behaviour of FMCG (fast moving consumer goods) products. Online advertising had known as a dominant selling media and advertisement is necessary for any market to continue its function. This research is to explore direct and indirect impact of online advertisement on consumer buying behaviour. In indirect impact, Ads characteristics is mediating variable between online advertisement and consumer buying behaviour. Theoretical framework gathered from previous studies and articles and to conduct quantitative research, questionnaire used for collection of data. A cross sectional survey research design was adopted with universities students as the target population. Research is conducted in Islamabad, Pakistan and sample size of this research is 240.To check the format of survey instrument pre-test was conducted and to check the suitability of questions and reliability, Cronbach’s alpha statistic were used. Direct and in direct impact of independent variable on dependent variable is measured through correlation and linear regression. Results revealed that online advertisement is positively related to consumer buying behaviour and it is significant factor which influence consumer buying behaviour but there is no mediation of ads characteristics in indirect relation because impact of ads characteristics on consumer buying behaviour is very less as compare to impact of online advertisement. Supervisor:- Fizzah Khalid Butt