We compared the diversity of amphibians and reptiles in forest of vega, gallery forest and savannas in flooded savannas ecosystems. One sampling was conducted at three sites in each climatic season, using visual methods and encounter barriers of interception with pitfall traps. Sampling effort for each type of vegetation was 252 hours, and 504 hours of pitfall traps. A total of 23 species of anurans and 37 species of reptiles (ten snakes, thirteen lizards, one worm lizard, four turtles and one crocodilian) were recorded. Most are new records for the northeastern region of Casanare department. The greatest richness and abundance of herpetofauna were found in savannas. The weather is not a determining variable in the richness but in the abundance of the herpetofauna. Savannas are very important for maintaining the structure of herpetofauna assemblages throughout the annual cycle, forests are areas of maintenance of diversity during the flood period.