The high prevalence of cases of water borne diseases in most cities in Nigeria is alarming. In these cities, there is
little documentation about the spatial variability of the incidence of the diseases. This study adopts GIS techniques
to investigate the spatial variation of water borne diseases in Ile-Ife, Nigeria. Data for the study were acquired
from IKONOS satellite imagery and topographical map from which essential features were extracted using digital
image processing techniques of Erdas Imagine 9.1 version. Structured questionnaire was also used to elicit
information on households’ socio-economic characteristics. Water samples were collected and analyzed using
standard microbial and chemical methods. The microbial count, pH and water hardness were interpolated using
Krigging interpolation technique in ArcGIS 9.3. The secondary data utilized for the study include land use data
and reported cases of water borne diseases from health facilities. Geocoding technique of ArcGIS 9.3 was
employed to match the addresses of the patients with the cases of water borne diseases. The results showed that
most reported cases of water borne diseases were due to environmental factors including poor environmental
sanitation and topography. This implies that a continuous negligence and under estimation of the role of these
factors in the spatial spread of the water borne diseases may increase the vulnerability and health risk of the people
in the area. The study recommends frequent treatment of wells and boreholes, improved environmental sanitation
and enhanced waste management strategies.