Species management should be based on accurate estimations on the size and density of the target population. In the case of the otter, these estimations are difficult to obtain due to their habitat, low densities and elusiveness, and these have relied mainly on surveys of animal signs or on specific ad hoc methods, and lately, in genotyping. We have applied newly-developed spatial capture-recapture model to estimate the otter population of the Tablas de Daimiel National Park by a spatially explicit capture-recapture of unmarked individuals using camera trapping-data together with distance sampling. The density estimated is 0.557 (±0.317) otters/100 ha, and we have achieved reliable information about activity, movements, and space use.