Suspension of magnetic nanoparticles (0.7 g/liter) obtained from Klebsiella oxytoca culture was injected intraperitoneally (1 ml), intramuscularly (in the hip; 100 μl), and subcutaneously (200 μl) or administered orally instead of drinking water for 2 days. The presence of magnetic nanoparticles was evaluated detected by MRI in 15 min and 2 h after injections and in 1 and 2 days after the beginning of oral consumption of the suspension. Magnetic nanoparticles were eliminated from the site of intramuscular and intraperitoneal injections and after oral consumption. The period of elimination after intramuscular and intraperitoneal injections did not exceed 2 h, while after oral consumption it corresponded to the time of gastrointestinal tract contents evacuation.