Poor sanitation and hygiene are still one of the pressing challenges in the developing world with not only serious health and but also non-health consequences. Diarrheal diseases, for example, are preventable by handwashing and hygienic latrine, still kill more than 4500 children every day, more than that of measles, malaria and HIV combined. Its non-health consequences include welfare loss, dignity, economic and financial losses...Vietnam had a rural sanitation coverage of only 65% despite the great amount of investment (mainly in hardware provision) in rural sanitation and hygiene over the last 25 years. Behaviour change interventions, therefore, are necessary if the country is to achieve Universal Sanitation and good hygiene by 2030 as it committed. Consequently, an understanding of the population’s sanitation and hygiene behavioural determinants is required in order to design efficient and effective intervention programs. This thesis is based on the RANAS model using data surveyed in Giong Trom district, Ben Tre Province (of the provinces with lowest rural sanitation coverage in Vietnam). It has 3 objectives: to identify behavioural determinants and factors associated to a range of sanitation and hygiene behaviours; to identify, measure and compare to health and non-health impact associated with different sanitation conditions; to propose and recommend evidence-backed interventions aimed at improving rural sanitation and hygiene. Having employed the logistic and multiple linear regression analysis, the thesis found the key factors associated with the following sanitation and hygiene behaviours: • Hygienic latrine ownership: Source of income, poverty certificate possession, instrumental beliefs, perceived cost. • Unhygienic latrine ownership (while already having hygienic latrine ownership): Location, disgust, user preference, personal norm. • Hygienic latrine regular use: Gender, vulnerability perception, Instrumental beliefs, user preference, descriptive norm. • Handwashing with soap: Knowledge, user preference, disgust, volitional self-efficacy. • Forgetting handwashing with soap: Gender, knowledge, user preference, disgust, descriptive norm, injunctive norm, volitional self-efficacy, motivational self-efficacy. In addition, the thesis didn't find clear cut evidence on the health impact of different sanitation conditions due to the fact that it isn't possible to attribute any diseases solely to poor sanitation. However, it found strong evidence that poor sanitation conditions had significant negative welfare impact on the households. Finally, it demonstrated how a recent intervention program -the WASOBA project- was successful in Ben Tre in increasing hygienic latrine ownership because it addressed directly the key determinant factors identified by this thesis.