ABSTRACT BACKGROUND AND OBJECTIVES: Pregnancy is characterized by a period when women's body suffers different changes. Between 50 and 80% of pregnant women refer low back pain, which may directly interfere with their quality of life. This study aimed at determining the prevalence of low back pain and its interference with quality of life of pregnant women assisted in the Family Health Strategy of the City of Cabo Frio. METHODS: Field cross-sectional study with pregnant women between the 13th and 36th week of gestation, with low back pain, assisted in a low risk pre-natal program. A demographic questionnaire, Roland Morris and WHOQOL-bref questionnaires were applied to evaluate low back pain and quality of life, respectively. Descriptive statistics and Spearman correlation tests were used and p