The research results on pregnant women during the covid-19 pandemic indicate that Covid-19 pandemic greatly affects the mental health of pregnant women. The analysis results of several studies show that anxiety in pregnant women during the Covid-19 pandemic has increased. The literature review research conducted by Heni Purwaningsih (2020) resulted that during the Covid-19 pandemic, most of the psychological changes in pregnant women were in the form of anxiety and depression. One of program to decreasing Maternal Mortality Rate/Infant Mortality Rate is with the OSOC method. The Continuity of Care model of midwifery care in OSOC clinical education (One Student One Client) is a method used by midwife students to collect data and assist pregnant women during pregnancy, childbirth, postpartum, new-born babies to family planning for the health of mothers and babies. The purpose of the study was to determine the effectiveness of OSOC (One Student One Client) in reducing the anxiety of third trimester pregnant women in facing childbirth and breastfeeding practices in the era of the covid-19 pandemic. The research design used was pre-experimental with one group pre-test – post-test design. While the number of samples was 13 pregnant women in the third trimester, and they were willing to be respondents. Sampling technique used was the purposive sampling. The data analysis and interpretation were bivariate and univariate. The bivariate analysis used the frequency distribution table, and the univariate analysis employed the Paired Sample T Test.The results of the study pointed that the average value (mean) of anxiety before being given the OSOC intervention was 9.3077 and the average value (mean) of anxiety after being given the OSOC intervention was 1.0769. The significance value (2-tailed) of the data was 0.002 (p < 0.05). Therefore, the results of the OSOC treatment before and after experienced were significantly changed. The conclusion was that OSOC is effective in reducing the anxiety of Third Trimester pregnant women in dealing with childbirth and breastfeeding practices in the era of the Covid-19 pandemic. This is an open access article under the CC–BY-SA license.