The purpose of the study is to validate the Work Addiction Inventory (WAI). The WAI is designed to assess individuals' addiction to work via self-report. Data were collected from 244 working professionals employed on at least a part-time (20 hours per week) basis. Results failed to replicate the three factor model found in the initial validation study (Bryan, 2009). A follow up exploratory factor analysis on the first half of the sample retained 15 items and suggested that the WAI consists of two underlying factors. This two-factor structure was found to cross-validate in a confirmatory factor analysis on the second half of the sample. The WAI subscale and total scores showed adequate internal consistency reliabilities. Convergent and discriminant validity was initially supported by relationships of the WAI scores to an existing measure of workaholism, a work engagement scale, and average hours worked per week. Also, WAI scores formed several clusters suggesting evidence of three workaholic types. Finally, evidence was found to suggest that the WAI accounts for unique variance beyond an existing measure of workaholism in predicting average hours worked per week and burnout In conclusion, psychometric properties of the WAI were partially supported by findings of the study.