The synthesis and characterization of NbSBA-3 mesostructured materials - the first hexagonally ordered mesoporous molecular sieves without extra framework Nb-oxide phase - are described in this paper. The effect of the synthesis medium (basic or acidic) and Nb source in the efficiency of niobium incorporation is discussed. A higher Nb content in the final material is reached when Nb(V) chloride is used instead of Nb(V) ammonium trisoxalate complex in the synthesis. All NbSBA-3 materials prepared in this work are very attractive catalysts in ODH of propane and epoxidation of cyclohexene and more effective than the corresponding NbMCM-41 and NbSBA-15 catalysts. (c) 2006 Elsevier B.V. All rights reserved.