Objectives: To observe differences between maternal and paternal prenatal attachment as a function of sociodemographic and clinical/obstetric factors.Methods: Quantitative descriptive correlational study. Instruments: Sociodemographic and Clinical Questionnaire; Maternal and Paternal Antenatal Attachment Scale (Portuguese version by Camarneiro & Justo). Assessments were conducted in antenatal clinics in Central Portugal.Participants: Couples (N=407), women and men in the second trimester of pregnancy.Results: Significant differences in maternal prenatal attachment were observed as a function of age, education, socioeconomic status, pregnancy planning, previous pregnancies, pregnancy interruptions and gestational age. Significant differences in paternal prenatal attachment were observed as a function of age, number of children, socioeconomic status, occupational status, family household and pregnancy planning.Conclusions: Women and men present variations in prenatal attachment according to some sociodemographic and clinical variables. These results should be taken into account in interventions focused on the promotion of prenatal attachment.