Introduction: Inadequate caregiving conditions interfere with successful health and development outcomes. Access to appropriate information can result in improved health and development outcomes in children. Health promotion text messaging, a primary mHealth strategy, has been implemented in various countries to reach communities where the majority of the population may be living in poverty and lacks access to information and health services. This systematic review investigated what effect the provision of information regarding health and development in young children, using text messages, has on caregiver behaviour and child outcomes. Method: The review was conducted according to the PRISMA-P (Preferred Reporting Items for Systematic review and Meta-Analysis Protocols) guidelines. Studies were retrieved from Scopus, MEDLINE, PubMed, Web of Science Core Collection and Cochrane library using primary search phrases. The search was not limited to a specific period. Thematic analysis was used to organise and synthesise the information extracted from selected studies into main and sub-themes. Results: In total, 19 studies were identified, including randomised controlled trials (RCTs) (n = 13, 68.42%), observational studies (n = 3, 15.79%) and non-RCTs (n = 3, 15.79%). Message content included educational information regarding health and development (89.47%), reminders (36.84%) and caregiver support (52.63%). The majority of studies (n = 17; 89.47%) found statistically significant positive effects of text message intervention on caregiver behaviour. Text messages also affected child outcomes, with 15.79% (n = 3) of studies reporting a positive effect. Conclusion: Text messaging is an effective tool to influence caregiver behaviour and child outcomes in health. There is however limited evidence regarding text message intervention effectiveness on child development, both in quality and in quantity. More research, especially in low- and middle-income countries, is necessary.