Purpose: This study investigated the prevalence of postpartum depression (PPD) and explored associated factors among mothers attending postnatal care in Bhutan. Methods: A cross-sectional study was conducted from August to November 2023 at a national referral hospital in Thimphu, the capital city of Bhutan. In total, 314 mothers were recruited. Sociodemographic, psychosocial, obstetric, and infant-related data were collected using questionnaires. The Edinburgh Postnatal Depression Scale, with a threshold of ≥11, was employed to screen for PPD, and logistic regression was used to test the potential factors. Results: The prevalence of PPD was 14.97%. Mothers with a perceived change in body image (adjusted odds ratio [AOR], 4.40; 95% confidence interval [CI], 1.91-10.17; p=.001), perceived heightened stress after delivery (AOR, 3.74; 95% CI, 1.45-9.67; p=.006), poor relationship with inlaws (AOR, 2.57; 95% CI, 1.24-5.30; p=. 011), and negative birth experience (AOR, 2.42; 95% CI, 1.17-5.00; p=.016) demonstrated significantly higher odds of developing PPD. However, mothers with a higher monthly family income (Bhutanese ngultrum [Nu.] 20,000 to <50,000; AOR, 0.35; 95% CI, 0.13-0.92; p=.033), ≥Nu. 50,000 (AOR, 0.37; 95% CI, 0.13-1.07, p=.067) compared to <Nu. 20,000, and advanced gestational age (37 to <41 weeks; AOR, 0.25; 95% CI, 0.09-0.71; p=.009) and ≥41 weeks (AOR, 0.08; 95% CI, 0.00-0.75; p=.028) compared to <37 weeks had significantly lower risks of PPD. Conclusion: To mitigate the prevalence and risk of PPD, prioritizing screening strategies and interventions may benefit mothers with perceived changes in body image and heightened perceived stress after delivery, poor relationships with in-laws, and those with negative birth experiences.