There has been, and will be, a spectacular growth in the number of call centers on both sides of the Atlantic. So far, however, empirical evidence is lacking as to the operational determinants of caller satisfaction in call centers, despite the multitude of call performance metrics registered in many call centers. Undertakes an empirical assessment of the relationship between caller satisfaction and a number of critical variables. The results are astonishing. Of all the critical operational determinants only “percentage of calls closed on first contact” and “average abandonment” have a significant, albeit weak, influence on caller satisfaction. Concludes, therefore, with a call for more research into reliable and valid predictors of caller satisfaction.