Intolerance of uncertainty (IU) has been posited as ubiquitous across experiences of anxiety; however, studies testing how IU impacts behavior remain scant. The current study examined the impact of IU on performance during a keyboard typing task, a relatively complex and common behavior. A total of 40 members of the university community completed the task and measures of IU, trait anxiety, negative affect, and state anxiety. Heart rate and skin conductance were also assessed during the task as indices of state anxiety. IU was independently and substantially associated with slower typing speed (part r = −0.68) beyond other measured psychological and physiological variables but was not associated with typing errors. Prospective and inhibitory IU, as manifestations of IU, did not seemingly differ in their relationship with performance. IU may negatively impact day-to-day behaviors and contribute to undesired consequences. Further research is needed to explore whether this relationship warrants consideration in models of anxiety disorders.