Russia; 6-8 L'va Tolstogo St., 197022 Saint Petersburg, Russia; 4 Leningrad Regional Clinical Hospital; 45-49 Lunacharskogo Prospect, 197022 Saint Petersburg, Russia In the retrospective multicenter study during [2007][2008][2009][2010][2011][2012][2013][2014][2015][2016][2017] we included 59 oncohematological patients with mucormycosis and 541 patients with invasive aspergillosis. Our study showed that mucomorhycosis more often developed in children and adolescents (p = 0.001), and after «graft versus host» disease development (p = 0.0001). Patients with mucormycosis were more immunosuppressed: severe neutropenia was in 88 % vs. 82 %, median duration of neutropenia -30 days vs. 14 days, p = 0.0001, lymphocytopenia -77 % vs. 65 %, median duration of lymphocytopenia -25 days vs. 14 days, p = 0.001. The main sites of infection were lungs, nevertheless in patients with mucormycosis it was less frequent (73 % vs. 97 %, p = 0.02), but more frequent were ≥2 organs involvement (42 % vs. 8 %, p = 0.001) and paranasal sinuses involvement (15 % vs. 6 %, p = 0.04