Behaviour of dental health maintenance needs to be done during pregnancy. Pregnant women should be aware of the importance of maintaining dental and oral health during pregnancy for herself and the fetus thus avoiding the occurrence of oral disease that can affect pregnancy. Bad oral health conditionon pregnant women may adversely affect pregnancy and foetal development. The purpose of this research is to understand the level of knowledge, attitude, and action of dental health maintenance with the level of dental hygiene on pregnant women in of Puskesmas (Public Health Centre) Tegowanu Grobogan Regency working area.The type of this research was quantitative descriptive research, using cross sectional design. The population in this research was a number of 124 pregnant women. Sampling technique was using purposive sampling. In this case, the writer took 20% from population that was counted 25 respondents. Measuring tool in this study was questionnaire and examination sheet of dental hygiene level. Data obtained from the research was displayed in form of frequency distributiontable and analysed by using cross tabulation.These research results indicated that the most of pregnant women in the Puskesmas Tegowanu had the knowledge, attitude, and action in the moderate category with a moderate level of dental hygiene as well. The conclusion obtained that there is a correlation between behaviour (knowledge, attitude, and action) of dental health maintenance with dental hygiene level in pregnant women at Puskesmas Tegowanu Grobogan Regency. It is expected that pregnant women increase their knowledge, improve awareness, and responds positively about dental health maintenance, as well as pregnant women need to maintain the cleanliness of teeth. It is expected that Puskesmas Tegowanu gives more intensive in providing information about dental health care.