The financing of technology based start up companies is deserving great attention, not only from of the investors' community but also from public agents, due to the economical and social earnings attributed to such companies. These accomplishments depends, however, on knowledge and sophisticated abilities to work with risk factors associated to such companies, related to their technology level and to the nature of the opportunities pursued. The extension of the risks involved and the complexity of the necessary instruments to deal with them lead to a recognition of this type of financing as a distinct investment, namely venture capital. Venture capital has its beginning in 1930, with investments made by a few wealthy American families. The following decade records the appearance of the first venture capital company, which comes to establish the operation paradigm of an industry. In the United States, this industry invests about a hundred of billion of dollars a year and perform the whole venture capital cycle: from Fundraising with the investors, to funding of start up companies and, finally, the harvesting and the distribution of results to the investors. In Brazil, this industry began to be structured following the Instruction CVM 209, (1994), which regulates funds denominated Mutual Investment Fund in Emergent Companies. Estimates suggest that in 2000, it was a US$ 1 billion dollar industry. One of the greatest barriers to the development of this industry is the acquisition of the technical knowledge on the management and evaluation of Funds that acquires assets non negotiable in the stock markets. The existing knowledge is, to a large extent, of private nature and treated as industrial secret. This work, of exploratory nature, is an incursion in the study of evaluation algorithms of venture capital funds, proposing improvements in existing evaluation models. Traditional evaluation models, like that of the Multilateral Investment Fund (MIF) use the historical return of this kind of investments in an attempt to estimate the performance of the fund. The objective of this dissertation is to modify the model of Fund performance developed by MIF to make possible a risk analysis beyond the expected return. This risk analysis will be accomplished by the evaluation of each company invested by the Fund. By simulating the terminal value of these companies, it will be possible to obtain a return distribution for each investor starting from the capital contributed to the fund. Such an instrument will be of great value not only in the selection of investments (allowing the investments to be selected in agreement with the exposure level that the manager wishes to assume), but also in the management of these discrete investments (allowing that are made decisions that maximize the expected return for the investors).