Objective This study aimed to assess the effect of dietary patterns during pregnancy on anaemia. Design, Setting and Participants A case–control study with propensity score analysis was conducted among pregnant women selected from five health facilities in North Shewa Zone, Ethiopia from November 2018 to March 2019. A multivariable conditional logistic regression model was applied after propensity score matching to assess the effect of dietary patterns on anaemia, and a p < 0.05 was taken as significant. Four hundred and seventeen pregnant women were included (105 cases and 312 controls) with a 1:3 case-to-control ratio. Cases were pregnant women with a haemoglobin level <11 gram/Deci litter (g/dL), and controls were pregnant women with a haemoglobin level ≥11.0 g/dL. Results A low dietary diversity score (adjusted odd ratio (AOR) = 2.14; 95% confidence interval (CI): 1.24, 3.69), reducing food intake (AOR = 6.89; 95% CI: 3.23, 14.70) and having no formal education (AOR = 3.13; 95% CI: 1.18, 8.32) were associated with higher odds of anaemia among pregnant women. Conclusions During pregnancy, intake of a low diversified diet, reduced food intake and low educational status were associated with higher odds of anaemia. Dietary counselling should be emphasised and strengthened in the existing prenatal health service program, with women strongly encouraged to increase their diversified food intake instead of reducing it during pregnancy.