The present dissertation intents to analyze the consistence of performance in stock funds in Brazil, from july/1994 to june/2001. We search the answer to the following question: through the analysis of times series of returns of stock funds in Brazil, is it possible to determine the most likely winners in the future? In other words: the performance of stock funds is consistent along time, allowing for the building of models with predictive power? The methodology applied was a quantitative approach, prices with complete information. I analyzed time series of financial returns of stock funds. The tests for consistence of performance were Contingency Tables 2X2 (with risk adjustment and without risk adjustment through alfa s of Jensen) and Portfolio Change Measure (PCM). The outcomes presents a pattern of consistency between the 1st and the 2nd periods analyzed. This standard is absent between the 2nd and the 3rd periods. The observed pattern of consistence is stronger for the worse performance. We applied tests to detect and measure the effects of survival bias and transaction costs in the returns of funds. The outcomes, obtained trough the analysis of the weighted portfolios and the statements of sources and uses of cash, are the absence of survival bias and effects of transactions costs in the returns of the stock funds analyzed. The performance of the stock funds analyzed must to be considered to be unsatisfactory.