During my 11 years as dean of admissions at the University of Chicago Booth School of Business, I reviewed every M.B.A. application that came into Booth.

It was daunting. But as head of business school admissions, I believed that if an M.B.A. candidate invested the time to apply I had a responsibility and ethical duty to give every application a full assessment. Had we utilized a pre-screening process to immediately filter out certain applications (e.g., test scores or GPA), we would have missed out on many exceptional individuals who went on to be fabulous business school students.

Needless to say, I met thousands of prospective students and reviewed more than twice as many M.B.A. applications. I made a point to consider every detail that would aide in making the final admissions decision. Through this process common M.B.A. applicant tendencies emerged, both negative and positive. Over the years it became apparent that the more negative traits were a reoccurring kiss of death for M.B.A. hopefuls, presented here as the "7 deadly sins."

Sin 1. Misrepresenting the facts: Here's what I believe: M.B.A. applicants who are less than honest in the application process are not necessarily dishonest people. Because business school admissions is especially competitive, candidates yield to pressure that results from believing what they bring to the admissions committee is not as impressive as what others may offer—so they take certain "liberties" with the facts.

While suspicious embellishment of your application will certainly weaken your chances, fabrication will kill it. I recall one M.B.A. applicant who said he was a Navy Seal, a piano virtuoso, and had won a national humanitarian award. Naturally, I was very impressed. Unfortunately, none of it was true. As the saying goes, "Just Say No" when tempted to exaggerate or misrepresent facts in your M.B.A. application. And never, ever lie. Believe me, you will be found out.

[Get more advice on how to get into business school.]

Sin 2. Rude or arrogant behavior: Business schools have high expectations for students they accept into their programs. Thus, there is never an excuse for less-than-polite or immature behavior. Yes, we all have bad days. But when interacting with the M.B.A. admissions office in any capacity, it is imperative to be professional, courteous, and accommodating.

Business schools and M.B.A. programs highly value personal character and confidence. But one's confidence can easily be interpreted by others as arrogance, so be careful. Demonstrate confidence but avoid conceit. A splash of humility doesn't hurt. In fact, it may show authentic confidence.

Sin 3. Too much contact: If you have a legitimate question, by all means, ask the admissions office. But don't overdo it. Avoid excessive contact or weekly E-mails to the admissions committee reminding them of your "strong interest," and remember to avoid the above sin of rude or arrogant behavior.

M.B.A. programs are charged with preparing future leaders of business and value applicants who can successfully walk the line between persistence and annoyance. The latter is often interpreted as desperation and truly hurts your appeal.

Sin 4. Not following directions: If you are asked to submit a 750-word essay, don't submit 1,000 words. If you are asked for two letters of recommendation, don't send seven. This behavior begs the question: If you cannot follow simple directions on the application, how will you follow directions and procedures as an M.B.A. student?

Sin 5. Sending wrong or unproofed information: There is no excuse for sending M.B.A. application essays that have numerous misspelled words or grammatical errors. Let spellcheck be your friend. And always have someone review your work.

Moreover, be sure to double check the mailing address before sending in your application. Let's say you're applying to the M.B.A. programs at Wake Forest University's Babcock Graduate School of Management and Vanderbilt University's Owen Graduate School of Management. If you send an essay that you wrote for Vanderbilt to Wake Forest, you may as well remove Wake from your list, because they will remove you. Believe me; it happens.

[Read more tips on how to write M.B.A. application essays.]

Sin 6. Asking questions you could answer yourself: Do your homework and take the time to know the basics. Steer clear of asking questions you can easily find answers to on your own, such as "What are your application deadlines?" or "Do you offer financial aid?" When an M.B.A. applicant asked me these questions, I made a note for future reference, and it was not because I was impressed.

However, if there are aspects of an M.B.A. program that is of particular interest to you such as a study aboard program, it's OK to ask for more details. This shows that you are taking the time to look deeper into the program's offerings and considering a variety of elements that make that business school special.

[Learn how to choose your M.B.A. concentration.]