References to procrastination have been dated back to as long as 3,000 years ago. However, research on procrastination is ironically enormously behind the curve in active research on its antecedents and effects. Academic procrastination is a unique outlet of procrastinatory tendencies and is the object of much less scientific research. Academic procrastination occurs when students needlessly delay completing projects, activities or assignments and has been linked to lower academic grades, poorer well-being, and more stress. Studies have found procrastination to be a vital predictor of success in college and the development of a scale upon which to measure it could be quite profitable to colleges and universities. Numerous scales such as the Lay (1986) General Procrastination Scale, the Solomon and Rothblum (1984) Procrastination Assessment Scale for Students, and the Choi and Moran (2009) scale have been used to measure procrastination. However, the Tuckman (1991) Procrastination Scale is the most widely-used scale to identify academic procrastinators.The current study examined these scales as compared to a new scale, the Academic Procrastination Scale (APS). The main goal of the current study was the development of a superior academic procrastination scale. The 25-item APS was originally developed in a pilot study using 86 undergraduate college students and was based on six different characteristics of procrastinators: Psychological belief about abilities, distractions of attention, social factors, time management skills, personal initiative, and laziness. The current study examined the relationship between the APS and the personality trait of conscientiousness and the predictive ability of the APS in regards to academic success as compared to the other procrastination scales.In the current study, a total of 681 participants responded to a survey. Participants were, on average, 21 years of age and came from diverse academic majors and demographic backgrounds. The APS exhibited greater reliability and internal consistency, á = .94, as compared to the four other scales. The APS also exhibited ample convergent validity and was significantly correlated with the other scales. The APS was also significantly related to Grade Point Average (GPA); as individuals procrastinated more, they possessed a significantly lower GPA. Yet, the APS proved far superior at predicting grades in school as compared to the four most widely-used procrastination scales. The APS even added incremental validity beyond these four scales in predicting semester grades. The APS also predicted variance in grades beyond a well-known personality predictor, conscientiousness. Moreover, scores on the APS fully mediated this established relationship between conscientiousness and grades.A factor analysis of the APS revealed one underlying factor, seemingly indicating that the scale was measuring academic procrastination. Test bias could possibly destroy a scale’s validity and was therefore assessed using two different procedures. An Analysis of Variance revealed that scores on the APS did not systematically vary with such irrelevant variables as gender, ethnicity, academic major or academic year. The Lautenschlager and Mendoza (1986) approach found that scores did, however, vary across ethnicity with Caucasians exhibiting a higher GPA across all levels of the APS when compared to African Americans. This trend was also found for the Tuckman scale, however. However, this bias could potentially be explained by GPA varying across ethnicity with Caucasians exhibiting a significantly higher cumulative GPA as compared to Hispanics or African Americans. Although the internal consistency of the APS was quite high, it is also symptomatic of redundant items. Thus, the possibility of reducing the scale to five items was assessed and validated. This shortened scale also exhibited adequate reliability, á = .87.Scholastic Aptitude Test (SAT) scores are used across the country to select students on the basis of success in college. However, both the APS and SAT uniquely predict college grades and together, account for 16% of the variance in college grades. It is even proposed that the current scale be used in conjunction with SAT scores to predict success in college. The APS could add significant validity to such a collegiate selection procedure. If procrastination is consistently found to have negative consequences, then students who exhibit higher scores on the APS could also be remediated in educational settings. Thus, based on results from the current study, the APS could be used as a valid, reliable, and instrumental tool within the educational community.