ObjectiveThe objective of this study was to determine the prevalence and determinants of unintended pregnancy among reproductive age women in Bahir Dar town, Northwest Ethiopia.ResultThe prevalence of unintended pregnancy was 15.8% (95% CI 13.8%–17.7%). Single women (AOR 0.18; 95% CI 0.08–0.40), women living away from their husband (AOR 4.18; 95% CI 2.64–6.61) and women with no access/exposure to mass-media (AOR 1.89; 95% CI 1.13–3.15) were more likely to have unintended pregnancy compared to their counter parts.Electronic supplementary materialThe online version of this article (10.1186/s13104-018-4016-z) contains supplementary material, which is available to authorized users.