A study explored the contribution of maternal physical health and/or breastfeeding problems to maternal mood (depression, anxiety, fatigue, irritability, confusion, vigor) at 8-weeks postpartum. Nulliparous pregnant women (N = 229), ≥ 18 years of age, ≥ 36-week gestation, singleton pregnancy and with sufficient English were recruited in the study. Self-report questionnaire (pregnancy, weeks 1–4 postpartum) and telephone interview (week 8 postpartum) were used to collect the relevant data. A high burden of physical problems was classified as ≥ 3 problems (cesarean/perineal pain; back pain; constipation; hemorrhoids; urinary and bowel incontinence) at ≥ 2 time points. A high burden of breastfeeding problems was categorized as having ≥ 2 problems (mastitis; nipple pain; frequent expressing; over- or under-supply of milk) at ≥ 2 time points. Forty-six women (20.1%) reported having a high burden of physical symptoms, 44 (19.2%) had a high burden of breastfeeding problems only and 25 women (11.0%) had both. A high burden of breastfeeding problems alone or with co-morbid physical problems was significantly associated with poorer maternal mood at 8 weeks. It was stated that early, effective postnatal treatment of maternal health and breastfeeding problems can potentially reduce women’s risk for poor mental health. The study was published in the Archives of Womens Mental Health.