This paper describes research and development efforts in Tanzania aimed at improving the health and productivity of rural chickens. Scavenging local chickens (SLC) have the potential to contribute enormously to food security in Tanzania once off-take improves. This can be achieved through step-wise improvements in the SLC production system. In Tanzania, Newcastle disease (ND) has been singled out as the most devastating disease of SLC and studies on the thermostability of NDV4-HR, the use of local feeds as carriers for the vaccine and the molecular epidemiology of ND virus have been undertaken. ND extension packages are also being tested. TANZANIA has a human population of 30 million and land area of 945 000 km2. About 80% of the people live in rural areas where the per capita income is low. It has a relatively large livestock and wildlife population. There are about 15.6 million cattle, 10.7 million goats and 3.7 million sheep. There are 11 national parks, 18 game reserves and 56 game controlled areas, which occupy a total of 23.2 million hectares of land (Melewas 1999). The livestock industry contributes 18% to the gross domestic product (GDP) and 30% of agricultural GDP. About 70% of livestock GDP originates from cattle and 30% from other livestock, including poultry, which contributes about 16% (Melewas 1989a, b). There are about 400 veterinarians, the majority of whom are employed by government while others are self-employed either as private practitioners or owners of drug distribution businesses. There are more than 1000 paraveterinarians, or animal health and production technicians who have certificate and diploma level training. There is, therefore, enough qualified manpower to improve the production of poultry in Tanzania, if given adequate financial and other resources. The poultry industry in Tanzania is not well developed. Although chicken production on a commercial scale started in the 1960s, it has made minimal impact economically and nutritionally. The commercial sector has performed poorly because of the expensive and poor quality commercial feeds, diseases, veterinary expenses, unreliable supply of day-old chicks, and limited credit facilities. As a result, commercial chicken meat and eggs are expensive and consequently consumption is low. Under prevailing economic conditions, the scavenging local chicken (SLC) therefore appears to be a better alternative to the commercial chicken because it requires minimal inputs in terms of finance, manpower and land resources and hence the final product can be made affordably cheap. However, the SLC has been neglected and limited efforts have been made by government, nongovernment organisations (NGOs) and farmers to improve their health and productivity. Improved health and productivity of the SLC would have a direct positive impact on farmers’ income and nutrition. 1 Faculty of Veterinary Medicine, Sokoine University of Agriculture, PO Box 3019, Morogoro, Tanzania 2 Department of Veterinary Microbiology, Royal Veterinary and Agricultural University, Denmark