Teachers all over the world are aware that students struggle with fractional concepts and with elementary algebra. Support for this assertion can be found in a variety of research reports. The National Assessment of Educational Progress (NAEP), a United States report, indicates that students have recurrently demonstrated a lack of proficiency in these areas over the past twenty years (NCES, 2000). An analysis of the 1990 NAEP in mathematics achievement found that only 46 percent of all high school seniors demonstrated success with a grasp of decimals, percentages, fractions, and simple algebra. The inability to perform basic operations on common fractions has led to error patterns that emerge in learning algebra. In this article, the authors present a study which determines if a relationship existed between proficiency with common fractions and success in algebra and its results. Proficiency in this context indicates that not only is a student able to understand fraction concepts, but also that the student is able to manipulate fractions for accurate computation without the aid of a calculator. In this study, an "ex post facto" design was used to compare students' performance in elementary algebra and intermediate algebra with their ability to understand and manipulate fractions. (Contains 3 tables.)