Objective To determine the Prevalence and factors associated with pregnancy‐related complications among reproductive‐aged women in northwest Ethiopia. Methods A community‐based retrospective cross‐sectional study was conducted among 2367 mothers who delivered from November 2018 to April 2019. Two‐stage stratified random sampling technique was employed in clustered villages from three districts out of 10. Pretested and semi‐structured interviewer‐administered questionnaire was used to collect information on pregnancy‐related complications. A binary logistic regression model was fitted to identify the associated factors. Results Overall, 2335 (98.6%) women participated in the study. Mean age of respondents was 15.4 (SD ±3.2) years and 1763 (75.5%) of the women were below 18 years of age. The number of pregnancy‐related complications was 372 (15.9%). Severe headache and high fever were the most frequently reported complications. Having a history of known health problem (adjusted odds ratio [aOR] 10.0, 95% confidence interval [CI] 7.10–14.10), history of hypertension (aOR 3.90, 95% CI 1.10–14.20), heart problems (aOR 1.90, 95% CI 1.10–3.30), and living in urban areas (aOR 1.40, 95% CI 1.10–1.81) were the factors associated with pregnancy‐related complications. Conclusion The number of pregnancy‐related complications was high. Having a history of a known health problem, having a hypertension problem, having a heart problem, and being an urban resident were contributing factors.