This article analyzes the influence of the initial size of a microenterprise in its survival. For this purpose we used the database of the companies classified as microenterprises, taking into account the value of assets, established in 2009 in the Department of Magdalena. By fitting a logistic model we estimated the importance of the size of a microenterprise in the probability of survival at the end of 2012. The adjusted model shows a positive and statistically significant relationship between initial assets and the probability of survival in the period of study.