Objectives: The aim of the current study is to develop a valid and reliable instrument with psychometric qualities to measure effect of social media usage on eating behaviour in university students. Design: A thirty-eight-item draft scale developed by the researchers. After content validity, twenty-two items are remained and was used to collect the data. In the analysis of the data, confirmatory factor analyses were performed to test construct validity. For the reliability of the scale, Cronbach alpha coefficient was calculated for the whole of the scale. Setting: The participants attended from various departments of different universities in Ankara. Participants: The scale was administered to the study group consisting of 247 university students. Results: Four items that had total correlation value less than 0 center dot 40 were removed from scale. The reliability coefficient of the whole eighteen-item scale was found to be 0 center dot 928. Conclusions: It has been shown that the scale developed as a result of the validity and reliability analyses performed for the scale is a valid and reliable measurement tool and can be used in studies.