Background Several studies conducted to access the status of household food insecurity in Ethiopia show that the nutrition problem is still highly prevalent especially in pregnant women and children. This study was conducted in 2018 main harvesting season with the principal objective to assess the level of food consumption score and associated factors among pregnant women attending antenatal service at Shegaw Motta Hospital. Methods Institution based cross-sectional study was conducted among pregnant women attending antenatal care service at Shegaw Motta Hospital, East Gojjam Zone, Northwest Ethiopia. Primary data of 422 pregnant women were collected using interviewer administered structured questionnaire and a systematic random sampling technique was used to select study participants. The standardized World Food Program eight food groups English version questionnaire was translated to the local Amharic language and used along with the Ethiopian food composition table. The collected data were subjected to descriptive statistics and analyzed with SPSS software. Results From the total of 422 pregnant women, 1.9% (95% CI: 0.7–3.3) of the respondents food consumption score were poor, 16.6% (95% CI: 13.0–20.4) were borderline and the remaining 81.5% (95% CI: 77.5–85.1) had acceptable food consumption score. Residence, being rural or urban [AOR = 4.594;95%CI: 1.871–11.283, P = 0.001], religion status, being an Orthodox [AOR = 0.073;95% CI: 0.021–0.254, P < 0.0001], were factors associated with food consumption score. Conclusions Food consumption score among pregnant women seems to be highly unacceptable. Residence and religion were factors associated with food consumption score. Therefore, appropriate nutrition education should be given.