A study was done on tuberculosis patients registered at thernAddis Ababa TB Centre during the period September 1, 1989 to Augustrn31, 1990 to determine the rate of defaulting from treatment and tornidentify factors associated with it.rnAn initial chart review of 1206 new tuberculosis patientsrnregistered during the period September 1, 1989 to August 31, 1990rnwas carried out in order to determine the rate of defaulting. Thernoverall defaulter rate, specific rate by sex, age, and distancernwere calculated. A sample of defaulters(cases) was then selectedrnby simple random sampling and all the non-defaulters were taken asrncontrols. The cases and controls were traced and interviewed byrntrained research assistants using a pretested questionnaire. Therntwo groups were compared by social, demographic, and healthrnvariables.rnA high rate of defaulting of 82% was found. The rates ofrndefaulting were higher in males, in the older age groups and -inrnthose living nearer. Most of the defaulting occurred in the thirdrnand fourth months of treatment. Inadequate knowledge, negativernattitude to the TB centre and low educational level were found tornbe statistically significant risk factors for defaulting( p