An ecological study on species composition, relative abundance and habitat association of small mammals and the impact of human interference on their abundance and diversity was carried out in Nechisar National Park during August, 2008 to April, 2009. A total of 25 species of small mammals were recorded from the study area. Out of this, 20 species were rodents of three families and five species were insectivores of two families.Among the trapped small mammals, M. natalensis and A. dembeensis were the most widely distributed, whereas O. typus, C. olivera and E. rufescens were the least widespread in distribution. The population and density of small mammals were high during the dry season and less during the wet season. M. natalensis and A. niloticus were tapped from areas near human settlements as a commensal. The diversity and abundance of small mammals were correlated with different human disturbances in the area. Grazing, fire and deforestation were intensive, affecting the diversity, abundance and distribution of small mammals in the area.