As a therapeutic tool high dilutions (HDs) are always at the center of controversies due to problems to validate them as a function of Avogadro's number. Nevertheless, homeopathy is practiced around the world as a complementary and alternative medicine. The present study sought to evaluate HDs of homeopathic drug Ferrum metallicum (Ferr) 6, 30, 200, 1M, 10Mc and 50Mc, all of which except for 6c surpass Avogadro's number. Using HRTEM and EDS it was conclusively shown that: 1) all the investigated HDs of Ferr contained plenty of nanoparticles (NPs); 2) the size of NPs were within the quantum dots (QD) size range, except for 50Mc, in which larger particles were found (12.61nm); 3) NPs contained iron in various weight percentages; 4) the weight percentage of iron was highest in HDs 10Mc and 50Mc. © 2016 Elsevier B.V., All rights reserved.