Financial contagion is the act of spreading of a phenomenon within or from the stock markets sector. Stock markets are highly interlinked and happenings on one side of the world are bound to affect the happenings on another side of the world. The contagion can be because of domestic or international factors. The performance of Nairobi Securities exchange (NSE) was measured by the use of the monthly stock prices as provided by the data vendors at the NSE. This research paper used a quantitative research design where econometric models were used in the analysis. The entire population of the listed firms in the NSE was used. Primary data was collected from the licensed market participants at the NSE. Secondary data during the pre-crisis (April 2006 to July 2007) and post crisis periods (August 2007 to December 2008) were collected using data collection sheets. The data entailed NSE 20 Share Index, FTSE 100 and Standard and Poors and was analyzed using excel and SPSS tools. Hypothesis was tested at 0.05 level of significance and the null hypothesis was rejected at both the primary and the secondary data obtained.