Background: Unintended pregnancy is an important public health concern both in developing and developed countries because of its serious consequences for women and their families, including the possibility of unsafe abortion, delayed prenatal care, poor maternal mental health, poor child health outcomes, as well as increased maternal and infant morbidity and mortality. Objective: To assess magnitude and factors associated with unintended pregnancy among currently pregnant women attending antenatal care at Debre Tabor Town, Northwest, Ethiopia/2l019. Methods: Facility based cross-sectional study design supplemented by qualitative methods was conducted on 327currently pregnant women. Study participants were selected using systematic sampling method for the quantitative part and by purposive sampling method for qualitative part. Data were collected using structured interviewer administered questionnaire and by in-depth interview guide for the quantitative and qualitative parts respectively. Data were cleaned, edited, coded and entered in to Epi-data software Version 7.4 and analysis were undertaken using SPSS version 23. Bivariate and multiple logistic regressions were computed. Odds ratios and their 95% confidence intervals were computed to determine the level of significance. Thematic analysis approach were used to analyze the qualitative data. Results: The magnitude of unintended pregnancy in this study was 23.2% [95%CI: 19.0%-27.8%] (17.1% mistimed and 6.1 %unwanted).The major reasons of unintended pregnancy were short gap from previous pregnancy (32.89%), don’t have enough money to take care of the baby (25%), and not married (13.16%). Women who were unable to read and write AOR [3.97: (1.44, 10.93)], women who didn’t have discussion about family planning with their partners AOR [5.47: (2.69, 11.09)] and respondents who don’t have ever used modern contraceptive AOR [2.07: (1.02, 4.25)] were more likely to experience unintended pregnancy. Conclusion: The prevalence of unintended pregnancy in this study was comparable to other studies conducted in developing countries. Women’s educational status, not using modern contraceptive methods, discussion about family planning with partner and women’s attitude towards modern contraceptive methods were significantly associated with unintended pregnancy. Health promotion messages are needed to focus to improve the attitude of women about contraceptives as a primary prevention of unintended pregnancies. Key words: Unintended pregnancy, Debre Tabor, Antenatal care, associated factors, Ethiopia