The objective of this study was to evaluate the use of a 508-mm minimum length limit in conjunction with a 1-fish-per-day creel limit to determine its effectiveness in improving the size structure of the brown trout (Salmo trutta) fishery resource in the Lake Cumberland Kentucky tailwater. The ultimate goal is to increase the number of trophy (>508 mm) brown trout within the tailwater. When sample sites were combined, a significant increase in brown trout CPUE was seen across years for all size-classes. The time required to detect this increase in trophy brown trout was approximately 4 years and was dependent on growth. On a site-by-site basis, however, variability between sites tended to mask findings of significance. Such variability may lead to important management implications when planning a large tailwater-stocking regime. This study has shown that the trophy regulation resulted in increased numbers and sizes of brown trout within the Cumberland tailwater.