Abstract: The main objective of this study was to investigate the factors that affect growth of Micro and Small Enterprises (MSEs) in Addis Ababa City. The study tested impact of availability of technical and business management training for owners, the size of initial investment, the output of Micro and Small Enterprises (MSEs) as product versus rendering service, working in cooperatives versus working without cooperative on growth of Micro and Small Enterprises (MSEs) in Bole Sub City of Addis Ababa City Administration. Primary data, through structured questionnaire, was collected from random samples of 165 Micro and Small Enterprises (MSEs). Results revealed that Micro and Small Enterprises (MSEs) whose owners attained training, started business with high initial investment, engaged on the service sector, and established in non-cooperative form have better growth than those whose owners/operators did not attend training, who started with low initial investment, those engaged on production sector, and those working in cooperatives respectively. Hence, the concerned government officials, nongovernmental organizations and other national economic development players have to work hand in hand in the area of training, availability of finance, formation and business sectors of Micro and Small Enterprises (MSEs) in the country.