Abstract: Kenya has experienced biological invasions some of which are considered to have significant consequences on the socio-economic status of affected communities. At the ecosystem level, they change community structure and composition. Available data on invasive species in the East African region shows that 34 different species of invasive plants have invaded Kenya. Notable examples of invasive species include Opuntia stricta (Haw) and water hyacinth (Eichhornia crassipes). This research was aimed at assessing the impact of the invasive O. stricta on other plant species and wildlife in the Tsavo East National Park, Kenya (TENP). The study area was divided into twelve transects which was 2km long and ten quadrats each 5m by 5m established systematically along each transect. Data on Opuntia stricta coverage, woody plants, dung of elephant to denote their presence was collected in each quadrat. ANOVA was conducted on Opuntia stricta coverage and confirmed that its distribution differed significantly per the sampled transects. Correlation between Opuntia stricta and elephant distribution and presence of woody plants was carried out. A positive correlation between the presence of elephants and O. stricta percentage cover was significant with r=0.37 and P=0.000 at α=5%. O. stricta cover and woody plant species had an insignificant positive correlation with P =0.177 at   5% . Findings of this study are crucial in any strategies adopted to formulate a management strategy for O.stricta in the TENP and similar ecosystems.