Workplace Incivility (WPI) has recently become a dominant area of research as a predictor of employee behavior at work. WPI is a menace in the workplace that creates dissatisfied employees who spend most of their time on non-productive tasks. Based on a sample of 504 employees of public and private sector institutions in The Gambia and Ghana, this article examines the impact of workplace incivility on employee counterproductive work behavior through the mediating role of Turnover Intention (TI). Using structural equation modeling, the results indicate a strong relationship between workplace incivility and Counterproductive Work Behavior (CWB) as well as a partial mediating role of TI in the relationship between WPI and CWB. Furthermore, the independent sample t-test and multigroup analysis show a higher level of WPI, TI, and CWB in Ghana compared to The Gambia. These findings contribute to the under-researched area of WPI on the African continent. This study also adds value to the existing, but sparse, literature on workplace incivility and may also be used as a guide for public and private institutions in their pursuit of avoiding workplace incivility as well as knowing its effects on institutional productivity. Finally, this study is the first of its kind to look at the existence of WPI in both public and private institutions from The Gambia and Ghana making country comparisons as well as looking at the impact of WPI on the performance of employees hence its relevance to the literature.