Short-term organ culture and primary cell culture of human aorta were used to study the effect of selective removal of low-density lipoproteins (LDLs) from the surrounding medium (LDL apheresis) on the lipid content of cultured tissue and cells, respectively. LDL apheresis was performed by passing the culture medium through immunosorbent containing agarose-bound goat antibodies against human LDL. LDL apheresis promoted the decrease of lipids of all classes in the cultured atherosclerotic plaque. However, only the cholesteryl ester level, but not free cholesterol, triglyceride, or phospholipid levels, was lowered in the cells cultured from the plaque. One may thus assume that LDL apheresis facilitates regression of lipoidosis by reducing the content of lipids in atherosclerotic lesions.