Dental plaque is a soft deposit sticking tightly to the tooth surface, consists of microorganisms that can multiply when the oral hygiene is not well-maintained. Plaque is formed by the accumulation of food debris which is not immediately cleaned, so the bacteria are accumulated in the oral cavity. Orthodontic Plaque Index (OPI) is an advanced method to measure the level of oral hygiene and the level of plaque during orthodontic treatment. The objective of this study was to determine the oral hygiene level of female students using fixed orthodontics. This study was a descriptive observational study with a cross-sectional design. The study employed the 1st-4th year students from School of Dentistry, Faculty of Medicine and Health Sciences, Universitas Muhammadiyah Yogyakarta aged 18-23 years old and the students have been using fixed orthodontic for at least six months. The subjects were selected by purposive sampling method to obtain samples that have inclusion and exclusion criteria. The oral hygiene level of fixed orthodontic appliances from 55 female subjects showed that 61.82% is at the moderate level. This study concluded that the female students who have been using fixed orthodontics have moderate level of oral hygiene.