The objectives of this paper are to investigate whether the integration levels achieved by Catalan companies are related to their choice of the options for Management System Standards (MSSs) and to research the relationships of the perceived adequacy of using new MSSs and Business Excellence Models (BEMs) with Integrated Management Systems (IMSs). To test these relationships, data was obtained from 76 organizations which responded to a survey on IMSs, the options for MSSs and the possibilities regarding the addition of new MSSs and/or BEMs. The data was analyzed by means of a Multinomial Logistic Regression and Wald and Kruskal-Wallis tests, showing that one of the options, namely “rewrite the different standards with identical requirements”, was related to the integration level. However, no significant relationship between the options for using new MSSs and/or BEMs and the integration level was found. This paper contributes to the body of knowledge of MSSs and IMSs by relating the existing options for companies regarding their present and future usage of MSSs to their IMSs. Empirically, the results lead to the conclusion that efforts to increase the compatibility of MSSs should be made by all interested parties.