The objectives of this study were to assess the prevalence, the tetracycline resistance level and the genetic diversity of Escherichia coli isolated from organic pigs in comparison with conventional pigs. This study is integrated in a global European project, Safeorganic, funded trough CORE Organic II call. 25 organic and 25 conventional herds were considered in one slaughterhouse from April to October 2012. Colon content of 2 pigs per herds was sampled. For each pig, enumeration of E. coli and of tetracycline resistant E. coli (TET+E. coli) was determined.