Information about population structure and density is key part of conservation planning for crocodiles, yet little is known about Crocodylus acutus within its area of distribution and in the country in general. Population structure, density and habitat of this species were studied between September and December of 2006 in the Vía Parque Isla de Salamanca (VIPIS), Magdalena Department, Colombia. A total of 14 individuals were sighted in one creek and one lagoon complex out of the 14 marshes, 10 creeks, and one lagoon complex surveyed that comprise 8% of total of flooded and aquatic habitats in the VIPIS. An estimated density of 7.78 ind/km was calculated for creeks and 2.56 ind/ha for lagoons. The population structure was eight individuals (61.54%) for Class I, one individual (7.69%) for Class II, four (23.08%) for Class III, none for Class IV, and one (7.69%) for Class V. The size distribution found is considered unbalanced due to the low number of individuals sighted and their restricted distribution.