The effects of high-voltage screening were examined for perpendicularly and parallelly surface-ground titania rectangular bars. A screening field at or below which 30% of titania samples break electrically was applied to each group samples. After high-voltage screening, the surviving samples were subjected to mechanical strength measurement and the resultant strength distribution was compared with the original distribution. After screening, Weibull plots of perpendicularly ground samples bent to become convex curves while plots in the high-strength region remained almost the same, indicating that low-strength samples were selectively eliminated by the high-voltage screening, On the other hand, the screening effect on parallelly surface-ground samples was very small.