Playa Langosta is 1 of 3 nesting beaches in Parque Nacional Marino Las Baulas de Guanacaste, and is 1.3-km long. The 3 beaches (Langosta, Grande, and Ventanas) represent over 6 km of leatherback (Dermochelys coriacea) nesting. The use of passive integrated transponder (PIT) tags allowed us to identify each leatherback that nested at Playa Langosta. A total of 252 individual leatherbacks nested between the 1999–2000 and 2003–2004 nesting seasons. Of these, 63% (n = 158) were new turtles (untagged before), and 50% (n = 79) of the new turtles were originally PIT tagged on Playa Langosta. The majority of these turtles (54%) nested only on Playa Langosta, whereas a slightly smaller percentage (46%) nested at both Playa Grande and Playa Langosta. We recorded 904 encounters and 792 nests at Playa Langosta for the 5 nesting seasons of this study. Leatherbacks nesting at Playa Langosta ranged in curved carapace length from 125 to 164 cm and in curved carapace width, from 90 to 116 cm. Average internesting period was 9.6 days. For the first 4 seasons, data from excavated nests showed a decrease in percentage of hatching success from 68.9% to 30.4% in natural nesting conditions. A dramatic decline in emergence success from 57.2% to 9.3% occurred for these respective seasons. For the last 3 seasons, the hatching success of leatherback turtles in relocated nests was 52.4%, 18.9%, and 51.4%.