The purpose of descriptive research was to study the depression among teenager pregnant women receiving antenatal care at a community hospital in Chachoengsao province. The sample was 80 teenager pregnant women receiving antenatal care at a community hospital in Chachoengsao province. The data were collected between January to May of 2023. The instruments used for data collection were a questionnaire regarding personal data and a depression assessment form (9Q). The statistics used for data analysis were frequency and percentage.According to the results of the depression assessment (9Q) among teenager pregnant women, 43 percent were slightly depressed, 41 percent had no depression, 13 percent had moderate depression, and 3 percent had severe depression.The research suggestions were to be guidelines for care of young pregnant women in depression prevention, and they emphasized the need of mental health evaluation in both young pregnant women and their families. It should be assessed periodically throughout pregnancy and followed up after birth. The individual factors and the pregnant woman's context should be considered in the assessment in order to have access to the causes and prevention of depression comprehensively