Since smallholder farmers operate more than 80 per cent of all farms worldwide, their role is critical in the global food system. However, globalisation has exposed smallholder, resource-poor farmers to tremendous changes in consumer preferences and demand, sources of supply, new sources of competition, national and international regulations, and production technologies. To help smallholders cope with these changes and for more productive policy interventions, insights about why they choose to transition from a subsistence cattle keeper to a commercial cattle marketer are increasingly essential. This understanding of smallholder farmer decision-making is critical for both more effective and efficient agricultural value chains and overall rural development. The goals and values of farmers (Gasson, 1973, 1974) are believed to influence their farm decision-making and behaviour; however, the literature on this topic has been scant, particularly for smallholder farmers in developing countries. In addition, the current knowledge has been developed predominantly by quantitative methods, missing the nuances that a mixed-methods approach can offer. This thesis, therefore, investigates the farming values of smallholder farmers and how these values influence farmers' marketing decision-making. The study employed a novel mixed-methods research design with an interdisciplinary approach where multiple theories and methods were consciously integrated, and where the farmers' viewpoint was acknowledged and emphasised. A multilevel, sequential sampling method was used to collect qualitative data from 16 focus groups and quantitative data from a survey of 197 local cattle farmers in the North-western mountains of Vietnam. Multiple analysis methods were sequentially used, including content analysis (with some data conversion), descriptive statistics, factor analysis, regressions and path analysis. Qualitative analysis was supported by NVivo 12 Pro software; while quantitative analysis was conducted in SPSS\\(^¬¨vÜ\\) 24 and SPSS\\(^¬¨vÜ\\) AMOS 24. The mixed-methods approach in this study revealed more comprehensive insights into farmer values and their influence on the smallholders' marketing decision-making in an emerging economy context than previous research. The broad convergence of qualitative and quantitative evidence in the study confirmed two fundamental dimensions that underline the values of smallholders, professional- and family-oriented. Further analysis highlighted that professional-oriented values seemed more influential in the decision-making of smallholders who were cattle marketers while the role of their family-oriented values was stronger for the smallholders who were primarily cattle keepers. In this study, both tangible and intangible resources were examined to understand the mediating influences of farming values on behaviour. The Vietnamese smallholder farmers in the sample understood the regulative, normative, and cultural-cognitive issues in both the institutional context and their specific value chain. The study found that, in the local context, a behavioural shift from cattle keeping to cattle selling or marketing requires changes in the smallholders' values-based decision-making process, with an increased emphasis on professional-oriented values. This emphasis on professional-oriented values must be operationalised through enhancing both reputation and physical resources combined with developing a more commercially oriented mission and focusing market decision making on supporting farm solidarity. Third, a shift in the smallholders' perception of self-identity supports the transition from cattle keeping to bull-keeping to ultimately cattle marketing. Lastly, the age of farmers appears to be a supportive factor in fostering the positive influence of professional-oriented values on the marketing decision. The study has made a number of distinct contributions, including the theoretical extension of the farmer decision-making framework through integrating Gasson's (1973, 1974) value orientations with resource-based theory and an institutional perspective of value chains, and its application in a new cultural context. Hence, the understanding of farmer's values and their values-based decision-making is an important contribution for academics, agricultural practitioners, and policymakers.