Saccamoeba limax amoebae isolated from an aquatic biotope were found to harbor two different endocytic bacteria. By means of electron microscopy it could be shown that the first one was a rod-shaped Gram-negative bacterium considered as an endosymbiont. The second one developed elementary bodies (EBs) and reticulate stages (RBs) which are characteristic of Chlamydia-like bacteria, such as Parachlamydiaceae, which are known to replicate within free-living amoebae (FLA). Cocultivation assays with various FLA relevated a high degree of host specificity.