Postpartum depression (PPD) is a form of major depressive disorder affecting approximately 13% of women worldwide. Unintended pregnancies, reaching close to 50% of the pregnancies in the United States, have become a major health concern. While many physiologic and psychosocial causes have been analyzed, few studies have examined the relationship between unintended pregnancy and symptoms of PPD.A cross-sectional study was conducted using surveillance data from the Centers for Disease Control and Prevention's Pregnancy Risk Assessment Monitoring System (PRAMS) from 2009 to 2011. The PRAMS population-based random sample included women who have had recent live births and is representative of 78% of the United States population. The chi-squared test was used to examine bivariate associations. Binary logistic regression was utilized to study unadjusted and adjusted associations between PPD and pregnancy intendedness, as well as other demographic and clinical characteristics of mothers in the sample. Multicollinearity in the adjusted model was evaluated using variance inflation factors. Sampling weights were used to account for PRAMS' complex sampling design.Of the 110,231 mothers included in the sample, only 32.3% reported desiring the pregnancy at the time of conception. Women with pregnancies categorized as mistimed: desired sooner, mistimed: desired later, or unwanted were 20% (adjusted odds ratio [AOR] = 1.2; 95% confidence interval [CI]: 1.1-1.3), 30% (AOR = 1.3; 95% CI: 1.2-1.4), and 50% (AOR = 1.5; 95% CI: 1.3-1.7) more likely to experience symptoms of PPD, respectively, compared to women with desired pregnancies. Other factors found to be associated with experiencing symptoms of PPD were a gestational age of <27 weeks (AOR = 3.1; 95% CI: 2.5-4.0), having a previous history of depression (AOR = 1.8; 95% CI: 1.6-2.0), and being abused during or before pregnancy (AOR = 1.6; 95% CI: 1.4-2.0).We found that women with mistimed or unwanted pregnancies were more likely to experience symptoms of PPD. Our findings support the current US Preventive Services Task Force and American Academy of Pediatrics recommendations for an integrated approach to screening for depression, aiding in the maximization of intervention and early referral for women at risk for PPD.