The normal titanium levels in the blood of males between 24 and 66 years of age were found to be 11.2 mug/l (rsd 4.1). After oral administration of titanium dioxide containing capsules or as powder (anatas) it could be observed that the material can be absorbed from the gastro-intestinal tract. If two titanium dioxide qualities, having different mean particle sizes (0.16 mum and 0.38 mum), are administered orally, the latter shows less absorption, most likely due to agglomeration phenomena, The blood concentration/time correlation shows the type of curves which are characteristic for a persorption mechanism of absorption and reveal a high individual fluctuation. An increase of the administered dose by twice the amount shows only a tendentious response in the corresponding blood levels. The method of analysis was ICP-AES. A pretreatment of the samples in order to eliminate the organic matrix is necessary.