This research was carried out between December 2009 and July 2010 with the aim of identifying sources of the trematode Fasciola hepatica infection in sheep of the hacienda El Palmar, village President Chitaga municipality, Norte de Santander, Colombia. To this end, there were three quarterly samples for coprodiagnostico to sheep by the modified Dennis technique, just as we established three sampling places in the hacienda for harvesting of shellfish (510). Snails were classified taxonomically by morphological characteristics of the shell and dissection of the reproductive system. Trematode larval stages found in the intermediate host were described and photographed. Statistical analysis was performed finding standard deviation (%), coefficient of variation (%), minimum and maximum values using the program Statgraphics Centurion 5.2.14 (XV) and graphs and averages (%), was used Excel 2010. The prevalence of F. hepatica in the definitive host was 74.66% in the 75 sheep sampled, while the highest rate of infection in snails was 6.81%, the average total length of the rediae found was 812.64μm. The average length of the opening of the snails was 6.66 mm (2 / 3) of the total length 10mm. The dissection of complex penile (n = 50) showed that the average penis was 1.28x bags longer than the foreskin, an increase 4x microscope. Based on these results it is concluded that the Palmar finances the intermediate host of F. hepatica is Lymnaea cousini. It is also concluded that the high frequency of trematode may be due to favorable environmental conditions such as temperature and rainfall that allow the parasite to develop their full life cycle causing potential risk of infection in the population. This is the first record of an outbreak of sheep fasciolosis to 3465 msnm for this region and Colombia. It is recommended to continue working on this line of research to carry out the epidemiological map of the trematode F. hepatica in the province of Pamplona, Norte de Santander department.