Dietary behaviours are key modifiable factors that can significantly affect pregnancy outcome. An understanding of these behaviours, including their variability according to socio-economic status and cultural diversities, could guide the development of effective nutritional policies and programmes for pregnant women in Ghana amidst the growing burden of non-communicable disease (NCDs). This hospital-based study assessed pregnant women’s fat and fiber consumption and factors affecting this behaviour. The study employed a descriptive cross-sectional design and quantitative approach. Two hundred (200) pregnant women were recruited from the antenatal care (ANC) unit of the Presbyterian Hospital in Dormaa Ahenkro, Ghana, using convenience sampling technique. The Fat and Fibre Behaviour Questionnaire (FFBQ) was used to collect data for the study. The instrument was interviewer-administered. Statistical Package for Social Sciences (SPSS) version 25 was used to analyze the data. Overall, fat, fibre, and total index were 2.65 (± 0.49), 2.82 (± 0.78), and 2.71 (± 0.38), respectively. Factors significantly affecting fibre index were age (H(4) = 28.21, p < .001), educational status (H(4) = 28.30, p = .001), marital status (H(2) = 13.49, p = .001), ethnicity (H(3) = 23.92, p < .01), and community of residence (U(Nurban = 61, Nrural = 139) = 5097.00, p = .022). Only educational status (H(4) = 10.17, p = .038) and ethnicity (H(3) = 24.77, p = .001) significantly affected fat index. The findings highlight the need to scale-up public health programmes and research in Dormaa Central Municipality, particularly on maternal nutrition and related issues.