High levels of nitrate in drinking water can cause methaemoglobinaemia, cancer, hypertension, infant mortality and birth defects. The objective of this retrospective study was to investigate the spatial variation of nitrate concentration in the drinking water sources in Ethiopia. The study was conducted using the Ethiopian Health and Nutrition Research Institute water quality database from 1993 to 2006. The results in the study indicated that nitrate concentration in the water samples were varied from below 0.00mg/l to 1295.00mg/l throughout the country. The average nitrate concentration in the well water exceeding the WHO guideline was observed in Dire Dewa (104.8mg/l) and exceeding the threshold value were found in Somali (37.0 mg/l), Afar (34.9 mg/l), Harari (26.3 mg/l) and Addis Ababa Region (20.5mg/l). In the rest region, it was below the threshold value of nitrate. Nitrate in the spring water was below the threshold value except Dire Dewa and Harari region. Nationally, 15.3 % (n=186) of the wells, 10 % (n = 33) of the springs and 12.4 % (n=21) of the taps had nitrate concentration exceeding the threshold value of 20mg/l and 5.7 % (n = 70) of well water and 2.7 %( n = 9) of spring water samples had nitrate concentrations higher than 50mg/l. Water resources control management can be important at these areas and it needs to apply some actions to reduce or remove nitrate from drinking water.