Background: COVID-19 pandemic has negative effects on the mental health and well-being of pregnant women. However, the number of studies in which the effect of the COVID-19 pandemic on mental health and well-being of pregnant women was investigated from their perspectives was limited. Objective: This study was aimed at determining the effects of the COVID-19 pandemic on the mental health and well-being of pregnant women. Methodology: In this study, the phenomenological method, a qualitative research design, was used. The data were obtained from 33 pregnant women who were hospitalized in the obstetric ward through essays they wrote. Results: Two main themes were determined: (1) feelings of pregnant women during the COVID 19 pandemic, (2) thoughts of pregnant women regarding the COVID 19 pandemic. Conclusions: During the pandemic, the participating pregnant women experienced negative feelings and thoughts, measures such as social isolation affected their pregnancy process and daily lives directly or indirectly, and almost none of them used a coping method.