Background: Some studies suggest that favourable socioeconomic circumstances are associated with better parent-child relations but the documentation of such an association is limited and inconsistent. Few studies focused on infancy, few studies relied on objective measurement of parent-infant relations, and few studies included more than one measurement of parent-infant relations in the first year of life. Aims: To report the prevalence of objectively measured problems in parent-infant relations during the first year of life and to examine the association between socioeconomic circumstances and parent-infant relations in an unselected community sample of infants. Methods: Cross-sectional study of a community sample of children from birth to 10 months in 15 municipalities in Denmark, n = 11,765. The exposure variables were population register data about socioeconomic circumstances: (a) parents' education, (b) family composition, (c) parents' origin, and (d) parents' occupational status. The outcome variable was the health visitor's concerns about the parent-infant relation assessed at four home visits from birth to 10 months after delivery. Results: The proportion of children with concerns about the parent-infant relation was 10.5%, 7.8% at one home visit and 2.8% at two or more home visits. Logistic regression analyses showed that all four indicators of socioeconomic circumstances were associated with concerns about the parent-infant relation in the first year of life. Conclusions: The risk of problematic parent-infant relations were significantly elevated among, children of immigrant parents, and children of parents with shorter education and not in education or work.