Mortality rates were determined for common snook Centropomus undecimalis that had been hooked and released in different localities throughout southern Florida. Researchers and cooperative anglers caught, tagged, and retained 470 common snook ranging from 205 to 1,120 mm total length in 23 experiments during June 1991–April 1995. Live bait was used to capture 421 snook; 49 were caught with artificial lures. All snook were held in pens (9.1 × 2.4 × 1.2 m) for at least 48 h; 20.4% were held for 96 h (4 d), 30.8% were held for 120 h (5 d), and 3.2% were held for 288 h (12 d). Ten fish, or 2.13%, died within 24 h of capture. Hook location was the only variable that significantly affected release mortality rates (P < 0.0001); snook hooked in the throat or stomach (5.1% of the time) accounted for 40% of the total mortalities. No fish died in two separate control trials that examined the effects of handling, tagging, and holding common snook. These results should encourage resource managers to continue to use bag and size limits and closed seasons as tools to manage common snook populations. However, spawning aggregations that are heavily fished during the closed (fish cannot be retained) summer season may require additional protection because increasing effort could adversely affect reproductive output.