This review of current writing assessment practices focuses upon the adult population, an area significantly underrepresented within psychoeducational literature. As compared to other populations, such as K-12 students, there are few options for the practitioner wishing to evaluate adult writers by means of standardized assessment instruments. This review of literature discusses common approaches to written expression assessment. While indirect assessment and cognitive processing approaches are reviewed in brief, significant attention is given towards the traditional approach of direct writing assessment. Aspects of direct assessment methods include syntax, cohesion, sense of audience, spelling, and fluency. In addition to these factors, the role of story prompts, rater reliability, and affective variables are considered. The paper concludes with brief overviews of applicable standardized assessment instruments for written expression assessment of this population. Particular focus is given towards the Wechsler Individual Achievement Test-II (WIAT-II) and the more recent edition of the Wechsler Individual Achievement Test-III (WIAT-III). The authors contend that although the WIAT-II may have been an adequate instrument for direct assessment of writing ability in adults, test developers have failed to maintain a focus on this population in the more recent WIAT-III. This inadequacy is evidenced in the omission of grade-based scoring tables for college populations and lack of content appropriate writing prompts for adults. Implications for practitioners working with postsecondary populations are discussed.