This paper explores the effects that founding conditions have on the survival of new firms. A regression model which allows us to examine the role played by a number of different features of founding conditions on survival rates was estimated. The effect of founding conditions is estimated taking also into account that survival may be affected by current market conditions. Further, the model allows the effects of founding conditions to be transitory, and provides a way to assess how long such effects last. Using data on 118,114 Portuguese new firms observed over the period 1983 – 1993, we find that founding effects are important determinants of exit rates, and in some cases, they are more important that current conditions. In most cases, founding effects seem to persist without much of an attenuation in their effect on survival rates for at least several years after the founding of the firm.