This review article is devoted to our work in the area of MCM-41 type materials modified with iron species. Three types of matrices have been applied: silicate MCM-41, aluminosilicate AlMCM-41, and niobosilicate NbMCM-41. Iron was introduced by various methods: during the synthesis, immobilisation of ferroceneacetic acid (FAA), chemical vapour deposition (CVD), impregnation, cation exchange (IE) and template cation exchange (TIE). Three fundamental features of the prepared materials have been considered: (i) structure, (ii) iron state (coordination, oxidation level, reducibility), and (iii) catalytic activity. The latter was tested in isopropanol decomposition, oxidation of methanol, decomposition of NO, selective reduction of NO with propene, and hydroxylation/polymerisation of phenol.