Background <p>Breastfeeding is the gold standard for infant nutrition, yet maternal stress and anxiety, especially in the Neonatal Intensive Care Unit (NICU) or due to postnatal pain, can inhibit the oxytocin-mediated milk ejection reflex, leading to reduced milk production and early cessation. Music intervention has been proposed as a non-pharmacological strategy to mitigate these stress responses.</p> Objective <p>This systematic review and meta-analysis aims to evaluate the effect of music interventions on objective breastfeeding outcomes (milk volume and composition), salivary cortisol stress marker, and psychological well-being in breastfeeding mothers. Unlike previous studies, this review and analysis includes both term and preterm infants across diverse clinical settings and examines the impact of music on physiological (breast milk volume and composition, breastfeeding duration) and psychological outcomes (maternal stress and anxiety levels).</p> Methods <p>A comprehensive search of Scopus, PubMed, CINAHL, and Web of Science was conducted for Randomized Controlled Trials (RCTs) published up to 2024. Following PRISMA 2020 guidelines, studies were selected based on their investigation of the effects of music on breastfeeding mothers. The methodological quality of the included studies was assessed using the Cochrane Risk of Bias tool and GRADE framework for certainty of evidence. Data were synthesized both narratively and through meta-analysis where applicable.</p> Results <p>Six RCTs with a total of 696 participants met the inclusion criteria. Quality assessment confirmed that all trials somewhat adhered to protocols with “Some Concerns”. Meta-analysis indicated that music significantly increased breast milk volume both immediately and cumulatively (<i>Z</i> &gt; 1.96, <i>p</i> &lt; 0.0001) with low heterogeneity (I² = 4%). Additionally, music improved breast milk fat content and reduced maternal salivary cortisol stress levels (<i>Z</i> &gt; 1.96, <i>p</i> &lt; 0.00001) with negligible heterogeneity (I² = 0%) respectively. The overall certainty of evidence is rated as “Moderate to Low,” necessitating cautious clinical interpretation. This rating is primarily due to methodological heterogeneity in milk volume measurements, a lack of participant blinding, and the potential risk of publication bias.</p> Conclusion <p>As one of the first reviews to concurrently assess both physiological and psychological breastfeeding outcomes, findings suggest music therapy is a promising, non-invasive adjunct to lactation care. By potentially reducing maternal stress, it may improve milk quantity and composition. However, further high-quality, standardized trials are necessary to carefully evaluate its true clinical magnitude and determine its appropriate integration into routine protocols for long-term breastfeeding success.</p> Clinical trial number <p>Not applicable.</p>