Leatherback turtle (Dermochelys coriacea) nesting activity was monitored, individual movements via flipper tag recoveries and satellite telemetry were determined, and illegal egg collection was quantified at Tortuguero, Costa Rica from 1995 to 2006. Annual nest deposition was estimated at 199–1,623 nests per year; a Bayesian regression model suggests that leatherback nesting decreased by 67.8% between 1995 and 2006. Tag recaptures from fisheries bycatch and strandings have been reported from Cuba, Nicaragua, and the United States. Two leatherbacks were followed with satellite telemetry; 1 swam to Cuba and 1 moved into the northwest Atlantic Ocean. Minimum rates for illegal egg collection from 2000 to 2005 were estimated at 13.0%–21.5%.