SAPO-34 and MeAPSO-34 samples were prepared based on a standard literature procedure [1]. In fact, several kinds of transition metal were incorporated in the SAPO-34 structure, during the synthesis step, beginning with the same gel. As a result, samples of SAPO-34 and MeAPSO-34, presenting good crystallinity and also having similar surface area and microporosity, were obtained. It was observed that acid sites concentration depended strongly on their metal content. Metal incorporation in the SAPO-34 structure generally increased acid sites concentration but did not affect the acid strength distribution. (C) 2011 Elsevier B.V. All rights reserved.