The study's objective was to examine the relation between maternal mental health and infant dietary intake. A cross-sectional, population-based telephone survey was employed within a statewide sample of Maryland Special Supplemental Nutrition Program for Women, Infants and Children participants. A 24-h diet recall was performed using the United States Department of Agriculture Automated Multiple-Pass Method. Analyses presented were based on 689 mother–infant pairs. Overall, 36.5% of mothers reported introducing solids to their infants early (<4 months of age), and 40% reported adding cereal to their infant's bottle. Among 0–6-month-old infants, higher infant energy intake was associated with symptoms of maternal stress [β = 0.02; confidence interval (CI): 0.01, 0.04], depression (β = 0.04; CI: 0.01, 0.06) and overall maternal psychological distress (β = 0.02; CI: 0.003, 0.03). With early introduction of solids in the model, the significant associations between infant energy intake and maternal stress and maternal psychological distress became marginal (P's = 0.06–0.10). The association between infant energy intake and maternal depression remained significant (β = 0.03; CI: 0.01, 0.06). Among 4–6-month-old infants, intakes of breads and cereals were higher among mothers who reported more symptoms of stress (β = 0.12; CI: 0.04, 0.23), depression (β = 0.19; CI: 0.03, 0.34), anxiety (β = 0.15; CI: 0.02, 0.27) and overall psychological distress (β = 0.04; CI: 0.01, 0.07). Among 7–12-month-old infants, dietary intake was not related to mental health symptoms. Findings suggest poorer infant feeding practices and higher infant dietary intake during the first 6 months of age in the context of maternal mental health symptoms. Further research is needed to evaluate these effects on child dietary habits and growth patterns over time.