For nearly a decade, 35-month attrition rates in the volunteer armed forces have exceeded 25 percent. This Note, reprinted from Armed Forces and Society, v. 15, no. 3, Spring 1989, identifies the determinants of attrition behavior of high school students and graduates — the population groups most significant for recruiting today’s higher-quality force. In order to improve the capability to predict who is likely to stay and who is likely to leave, and to understand why attrition occurs, the authors employ a unique microdata set and specify a statistical model that analyzes male attrition behavior jointly with enlistment. The results suggest that attrition is higher among people who enter rashly and without firm career goals, who have history of employment instability, and who do not expect to obtain further education. Policy implications are discussed.