Abstract: Party Capability Theory hypothesizes that parties with greater resources, usually 'repeat players,' fare better in the judicial system and are better able to influence legal changes than 'one shotters.' The theory also points out that 'parties who have lawyers do better.' The theory has become most influential since its publication and has been tested by several studies. However, its importance has not been addressed in the accounting academic arena. The intent of this inquiry is to generalize Party Capability Theory to federal tax cases. The research sample consists of 1,010 trial court cases, 744 federal appellate court cases, and 29 U.S. Supreme Court cases rendered in 1992-2006. Summary statistics indicate that around 34.5% of trial court cases and 16.4% of federal appellate court cases involve pro se litigants. Success rate analysis indicates that the presumed stronger party does win more often in court than the presumed weaker party. However, logistic regression results show the opposite direction. That is, the presumed weaker litigant is positively correlated with case results and the presumed stronger litigant is negatively associated with case results. Surprisingly, pro se representation is positively associated with case results and it reaches a statistically significant level in trial courts. The findings of this study have practical implications for those subject to litigation.