Family planning plays a role in saving lives across the globe by preventing unwanted pregnancies. Mobile phone-based technology could be used to increase the uptake of contraceptives. In India, health-based mobile phone applications are used by women to make decisions about family planning. The purpose of this multidisciplinary research was to determine the impact of mHealth tools for family planning. The pathway to family planning decision-making was examined using a conceptual framework which was an integration of the theory of planned behaviour (Ajzen, 1985) and the model of change (BBC Media Action, 2015). This study also examined the influence of other factors relevant to contraceptive use that are not accounted for by the theory of planned behaviour, and whether these factors were associated with exposure to mHealth tools. To examine the association between exposure to mHealth tools for family planning and predictors of behaviour, data was collected from mHealth intervention areas in India. A post-intervention quasi-experimental study with a 2x2 factorial design was conducted among 831 men and women from the state of Bihar. A quantitative survey and focus group discussions were conducted. The quantitative data analysis evaluated the extent of influence that predictors of behaviour (beliefs, social norms, perceived behaviour control, and outcome behaviour) have on a woman’s decisions about family planning. The results indicated an association between exposure to mHealth tools and improved communication about family planning among various family members after receiving health information from a health worker (H1). A relationship between exposure to mHealth tools and increased support women received from their husbands and extended family (mothers-in-law specifically) and peers (H2) was also found. A further result showed that knowledge about family planning was greater among users of family planning (H4). In the present research, qualitative data was used to broaden the interpretation of the quantitative findings. A directed content analysis approach (Hsieh & Shannon, 2005) provided insights about women’s and men’s experience of family planning and mobile phone use. The key consideration for many participants was that information on mobile phones helps them to ascertain information available at the village level, because the information was accessed first hand and without any time lag. This research supports the notion that in cases where the mHealth tools for behaviour change have their foundations in psychosocial theories, they could be effective. Such tools have the potential to effect positive change by reaching out to populations living in resource-poor settings or lacking social authority. The replicability of the conceptual framework could be tested in other contexts. There is potential for organisations that are planning to design and implement technology-based tools to base the designs and content of the tools on theoretical principles using this framework.