Aim: To synthesize and integrate current international knowledge regarding nursing strategies for the provision of emotional and practical support to the mothers of preterm infants in the neonatal intensive care unit. Methods: A systematic review and meta-analysis was undertaken. Four English-language databases including EMBASE, PubMed (including MEDLINE), Scopus, and Web of Science were searched from January 2010 to October 2021. Original quantitative studies that were written in English and focused on nursing strategies for the provision of emotional and practical support to the mothers of preterm infants in the neonatal intensive care unit were included. Eligibility assessment, data extraction, and methodological quality appraisal were conducted independently by the review authors. A narrative synthesis of the review results and a meta-analysis were performed. Results: Twenty studies that were published from 2010 to 2021 were included in the review. Three categories concerning the review aims were identified: ‘nursing strategies related to mothers’ emotions and infant-mother attachment’, ‘nursing strategies related to mothers’ empowerment’, and ‘nursing strategies related to mothers’ participation in care process and support’. Eight interventional studies that reported mothers’ stress as the study outcome were entered into the meta-analysis. Interventions consisted of the educational programme, spiritual care, telenursing, parent support programme, skin-to-skin care, and guided family centred care. Significantly lower maternal stress was found in the intervention group compared with that of the control group (g: −1.06; 95% confidence interval: −1.64, −0.49; Z = 3.62, p < 0.001). Conclusion: This review identified and highlighted key nursing strategies used to provide emotional and practical support to the mothers of preterm infants in the neonatal intensive care unit. They included family centred care, skin-to-skin care, parent support and education programmes, interpersonal psychotherapy, spiritual care, newborn individualized developmental care and assessment programme, and telenursing.