Currently in Tanzania, training institutions for professionals in cross-cutting sectors such as forestry and agriculture do not adequately capture the role of forest and tree resources for food security and nutrition, leading to dependency on one sector – agriculture – to cater for food and nutrition diversity. This undervalues the fundamental role of forest ecosystem services for sustainable agriculture by regulating water flows, stabilizing soils, maintaining soil fertility, regulating the climate, and providing habitat for wild pollinators and predators of agricultural pests. Provision of education on sustainable forests and trees for food security and nutrition at all levels seems to be the most conceivable entry point to ensure that adequate knowledge and skills are imparted to professionals. The goals of this training manual are to: enhance the recognition and significance of forestry to food security and nutrition through the sustainable management and use of forests and trees2; enhance the food security and nutrition benefits from the forests and trees; enhance and stimulate research and training capacity; strengthen institutional frameworks by incorporating food security and nutrition objectives in forest management policies, programmes and projects; and develop value chains based on forest and tree resources for sustainable development in the country. The overall objective is to create awareness and enable increased investment in the forestry sector for food security and nutrition in Tanzania. This training manual is also meant to serve as a useful tool for sharing and exchanging knowledge and experiences across different regions (within the country) and beyond.