Household food insecurity in Tanzania is widespread even when the country experiences bumper harvest. Food insecurity is widespread and chronic that there is always a certain degree of household food deficit at a given part in a year. Despite the government’s efforts to improve agricultural production, food insecurity has persisted. Thus, this study was conducted to assess causes of food insecurity and coping strategies of smallholder farmers in Chamwino district, Dodoma region. Specific objectives were to: identify and examine the causes of food insecurity in households of smallholder farmers; identify and examine various coping strategies employed by smallholder farmers during food insecurity; and suggest possible ways that would be used to reduce food insecurity in households of smallholder farmers. Data were collected from 146 respondents including 120 household heads and two extension agents from four villages in Chamwino district and 24 key informants using questionnaires, researcher’s diary and checklist. Quantitative data were analysed by using Statistical Package for Social Science (SPSS) computer software and qualitative data were summarised and analysed manually. Causes of food insecurity include inappropriate use of the available food, poor storage methods and facilities, small farm size, low income and use of poor technology. The major types of food insecurity coping strategies were skipping meals and selling labour. In conclusion despite the food insecurity coping strategies, a serious food insecurity problem still persisted. The coping strategies were not sufficient to minimize food insecurity problem in the study area. Therefore, the government, NGOs and other stakeholders should: create awareness to farmers on proper use of available food, advise farmers on good storage methods, put more emphasis on smallholder farmers’ agricultural production, planning and implementing the diversified income generating activities and appropriate technology use. All stakeholders need to play an important role to ensure the availability of food in a sustainable manner and people have access to it.