A 305-406 mm protective slot and 4 fish daily creel limit, allowing harvest of 2 fish <305 mm, was placed on largemouth bass (Micropterus salmoides) in Lake Sutton during July 1989. The purpose of the regulation was to protect slot length bass and increase the angler catch rate for bass >400 mm. The objective of this investigation was to evaluate the regulation's effectiveness by comparing size distributions, PSD and RSD40 of fish captured by electrofishing and anglers, as well as angler catch rates of bass >400 mm, before and after the regulation change. Daytime spring shoreline electrofishing was conducted annually between 1988 and 1992. An angler diary program spanned 1986 to 1992. Post-regulation PSD and RSD40 values of largemouth bass captured by electrofishing were significantly greater than 1988 and 1989 values. Length of angler caught bass also increased after the regulation change. PSD and RSD40 values from angler diaries were significantly greater after the slot limit in 1991 and 1992 than during 1986 and 1987. Slight increases in bass condition (relative weight) and mean length at capture for Age 1, 2, and 3 fish were observed in 1991 and 1992, suggesting forage had not become limiting 3 years after the regulation change. The regulation was considered successful.