Daily angler logs were used to obtain lengths of 696 angler-caught largemouth bass (Micropterus salmoides) during January-May 1993 from Farm 13 Reservoir, Florida (2,600 ha), where a no-harvest rule was in effect. Sixty-three percent of these fish were caught by 2 fishing guides (and their clients) and 37% were caught by 19 other parties of anglers that fished without a guide. Angler-caught largemouth bass ranged from 254 to 648 mm total length (TL) with modal peaks at 381- and 457-mm length groups. By extrapolating angler log data into the catch estimate from an ongoing creel survey, we estimated 96 trophy largemouth bass (>635 mm) were caught by anglers from December 1992 through May 1993. Seventy percent of the largemouth bass were caught with live bait (golden shiners, Notemigonus chrysoleucas). Anglers fishing with golden shiners tended to catch larger bass than anglers using artificial lures. The mean length of bass (429 mm) caught with golden shiners was significantly larger (P < 0.05) than the mean length of bass (376 mm) caught with artificial lures. Mean length and length distributions of angler-caught bass varied significantly between the 2 fishing guides, and between 1 guide and anglers that fished without a guide. However, when the data collected by the 2 guides were combined, differences were not observed between the size of bass caught by anglers that fished with or without a guide. Anglers caught a significantly (P < 0.01) smaller percentage of largemouth bass <330 mm and >584 mm TL compared to those captured by electrofishing. The angler daily log program provided a reliable method for collecting data on lengths of largemouth bass caught by anglers where a no-harvest rule was in effect.