Background: Dental and oral health is very important because it can affect general health. Dental and oral health is related to attitude so it needs an effort to improve attitude through health promotion. Social media (Whatsapp) is one of the health promotion media that has the advantage of being an easy-to-use media for sending various kinds of messages. The use of Whatsapp can be an opportunity in achieving health information. Objective: The aim of this study is to determine the effect of dental and oral health promotion using social media (Whatsapp) towards the first year students attitude in the female student dormitory Universitas Muhammadiyah Yogyakarta. Methods: This study was a quasi-experimental study,one group pretest-posttest design. The research subjects were 70 students in the female student dormitory UMY who were given health promotion messages for 28 days through Whatsapp group. These message were pictures messages given for 13 days and video message given on day 14th. These message repeated on days 15 to 28. The data was obtained through pre-test and post-test. The analysis was Wilcoxon test. Result: The results were p value= 0,000 (p <0.05) showed significant differences in students attitude before and after the health promotion using social media (Whatsapp). Conclusion: There is an effect of dental and oral health promotion using social media (Whatsapp) towards the first year students attitude in the female student dormitory Universitas Muhammadiyah Yogyakarta