The first goal of this study was to test whether family interference with work (FIW) is positively related to increased workplace cognitive failure (WCF), which is defined as errors made at work that indicate lapses in memory (e.g., failing to recall work procedures), attention (e.g., not fully listening to instruction), and motor function (e.g., unintentionally pressing control switches on machines). The second goal was to determine whether recovery experiences (psychological detachment and relaxation) during free time on evenings and weekends can mitigate (weaken) the positive relationship between FIW and WCF. Results based on data collected from 118 water utility employees suggest that FIW is indeed related to more WCF, and that psychological detachment from work mitigates this positive relationship. It was relatively less evident that relaxation plays such a mitigating role. (Contains 1 figure and 2 tables.)