University educators everywhere are trying to assist students in improving their ability to write clear and correct business English. Business communication texts, in general, use several decades of research that have established a three-stage process: prewriting, writing, and rewriting (Collins & Parkhurst, 1996). Identifying and correcting errors in grammar, mechanics and style is part of rewriting, especially proofreading. As a basis for critiquing student work, previous research identifies which errors bother business people the most (Beason, 2001; Gray & Heuser, 2003; Hairston, 1981), and focuses and simplifies work on grammar and mechanics. Few students make frequent errors in all the categories. A statistical tool often used in quality analysis, the Pareto Principle, also known as the 80-20 rule, could prove useful in motivating students to improve their work. For students' errors in grammar and mechanics, this project proposed to analyze errors made by individuals to identify "the critical few" errors. Correcting these errors could improve writing up to 80 percent. The project involved a two-stage process to investigate the utility of the Pareto Principle as a device for setting priorities in the area of grammar, mechanics and style. Results identified the top three errors for attention across all student groups analyzed and for the aggregated groups. Across the classes, Pareto Charts demonstrated a consistent focus on three to six errors, so that, in the classroom, the instructor can concentrate on the "vital few" to improve writing quality. Using the results of this analysis, then, focuses instruction, practice, and grading on the areas that will produce the most improvement: (1) Writing concisely, including eliminating "there is" and "it is"; (2) Comma usage; and (3) Passive voice. Reducing the field of errors for students allows both the instructor and the student to focus, making the grammar/mechanics improvement challenge more manageable.