This report presents population projections for the period 2003 to 2025 for the Mara Region and its districts. The projections were made using a Cohort Component Method (Spectrum System), whereby three components responsible for population change, namely: mortality, fertility and migration were projected separately as well as HIV/AIDS prevalence. The projected components were then applied to 2002 midyear base population in order to come up with the desired projections from 2003 to 2025. The report gives mortality, fertility, migration and HIV/AIDS assumptions, which depicts Mara’s demographic and socio-economic future trends. The results include estimated population by sex in single years and five-year age groups as well as some demographic indicators. Population growth for the period 2003 to 2025 shows an increase in growth rates. The projections show that population growth rate will increase from 3.3 percent in 2003 (with a population of 1,410,328) to 3.7 percent in 2025 (with a population of 3,174,455). Sex Ratio at birth is projected to increase from 92 male births per 100 females in 2003 to 98 male births per 100 females in 2025. Mortality estimates show that Infant Mortality Rate (IMR) is expected to decline for both sexes from 120 deaths per 1,000 live births in 2003 to 70 deaths per 1,000 live births in 2025. Under Five Mortality Rate (U5MR) for both sexes will also decline from 201 deaths per 1,000 live births in 2003 to 109 deaths per 1,000 live births in the year 2025. The mortality projected estimates further show that the life expectancy at birth for females is higher compared to that of males. Life expectancy at birth for Mara will increase from 47 years in 2003 to 56 years in 2025 for both sexes. For male population, life expectancy at birth will increase from 47 years in year 2003 to 55 years in 2025, while for female population the life expectancy at birth will increase from 48 years in 2003 to 57 years in 2025. Fertility is projected to increase as TFR will increase slightly from 7.0 children per woman in 2003 to 7.1 children per woman in 2025.