Background This study aims to investigate the risk factors for poor adherence to BP monitoring within 3 months after discharge from the hospital in postpartum discharged HDP patients. Likewise, females with hypertensive disorders of pregnancy (HDP) in China should have a blood pressure (BP) evaluation continuously for at least 42 days postpartum and have BP, urine routine, and lipid and glucose screening for 3 months postpartum. Methods This study is a prospective cohort study of postpartum discharged HDP patients. After telephone follow-up was conducted at 1 week, 6 weeks, and 12 weeks after discharge, the maternal demographic characteristics, labor and delivery details, laboratory test results of patients at admission, and adherence to BP monitoring after discharge were collected. While logistic regression analysis was used to analyze the factors related to poor adherence to BP monitoring, the receiver operating characteristic (ROC) curve was drawn to evaluate the model’s predictive value for the poor adherence to BP monitoring. Results In this study, 272 females met the inclusion criteria, and poor adherence to BP monitoring was presented in 182 patients (66.9%). A multivariate logistic regression analysis identified the education level of high school or below (OR 2.787, 95% CI 1.452–5.351), parity (OR 1.622, 95% CI 1.007–2.612), and delivery gestational age (OR 1.254, 95% CI 1.053–1.493) as independent risk factors in predicting a poor adherence to BP monitoring. The ROC curve analysis indicated that the continuous variable delivery gestational age had a significant predictive value for the poor adherence to BP monitoring, which resulted in a cutoff point of 33.4 weeks. Parity had a limited predictive value, with a cutoff point of 2. The established prediction regression model combined education level, parity and delivery gestational age had the maximal area under the curve (AUC, AUC = 0.746) and better sensitivity (66.5%) and specificity (71.1%). Conclusion Poor adherence to BP monitoring is a common state in postpartum HDP patients after discharge. Females with an education level of high school or below, a parity of two or more, and delivered at gestational age ≥ 33.4 weeks were unlikely to adhere to BP monitoring after discharge.