Aim: To compare complementary interventions for improving weight gain in preterm infants via network meta-analysis (NMA). Methods: We conducted a systematic review and NMA across six databases, including randomized controlled trials (RCTs). Two reviewers independently extracted data and assessed bias. Analyses used a Bayesian framework in GeMTC software, with effects reported as standardizes mean differences (SMDs). Confidence In Network Meta-Analysis evaluated inconsistency, ranking and evidence certainty. Results: In total, 61 RCTs (n = 5858 infants) were analysed. Tactile kinesthetic stimulation showed greatest weight gain improvement (SMD 8.9, 95% CI 0.8–17). Multisensory stimulation (SMD 7.0, 6.2–7.9) and its combination with music therapy (SMD 7.9, 6.6–9.1) were also effective. Other beneficial interventions included kinesthetic stimulation (SMD 1.3, 0.091–2.5), massage (SMD 0.70, 0.39–1.0), and massage plus tactile stimulation (SMD 0.94, 0.044–1.9). Oral stimulation reduced hospitalization duration (SMD −0.49, −0.88 to −0.098). Conclusions: Tactile kinesthetic, multisensory stimulation and massage combinations significantly enhance preterm infant weight gain. These interventions should be considered in neonatal care protocols to optimize growth outcomes. Trial Registration: The PROSPERO registration number is CRD42024557428. © 2026 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.