This paper describes employer enterprise dynamics in Portugal for high-growth and gazelle enterprises for the period 1990-2007, using the methodology by Eurostat and OECD. It discusses stylized facts related to firm performance by size, sector and survival prospects, using two parallel perspectives, by turnover and by employment, when appropriate. It also discusses the importance of existing framework conditions, which may be hindering entrepreneurial activity, as well as current supporting mechanisms offered by the government to encourage start-ups and fast growing SMEs. Regulations and the unique cultural environment in which Portuguese firms operate seem to be instrumental to the understanding of their relatively poorer performance.