In recent years the studies analyzing the implementation and integration of management systems (MSs) have increased (see, e.g. Douglas and Glen, 2000; Karapetrovic et al., 2006; Salomone, 2008; Bernardo, 2014; Domingues et al., 2015; Bernardo et al., 2017). This is mainly because of the success in the implementation and certification of the quality MS (QMS) ISO 9001 and the environmental MS (EMS) ISO 14001. According to the last available data (ISO, 2016), the growth rate of certifications for ISO 9001 has decreased 0.2 percent and for ISO 14001 has maintained an 8 percent as in the previous year (ISO, 2016). As discussed in previous studies, organizations can have multiple function-specific MSs implemented and it is necessary to define the best strategy to manage all them in the most efficient way (Beckmerhagen et al., 2003; Bernardo et al., 2009). This strategy is proven to be the integration of these MSs into a single and more effective and efficient MS, the integrated MS (IMS), which aims to satisfy all the organization’s stakeholders (Karapetrovic and Willborn, 1998a; Beckmerhagen et al., 2003). The existing literature about the process of MSs integration is wide, analyzing mainly the aspects of the process (Douglas and Glen, 2000; Salomone, 2008; Bernardo et al., 2009; Gianni and Gotzamani, 2015; Gianni et al., 2017). General consensus has been achieved for all the process aspects except in one: the integration methodology. There is not a common and widely applied methodology or model that the organizations can follow in order to ensure a successful process and several possibilities have been proposed (AENOR, 2005; Karapetrovic, 2005; de Oliveira, 2013), and no international certifiable standards have been published proposing a guideline. This aspect is also related to the sequence in which these MSs have been implemented (sequential or simultaneous) which can condition the integration methodology applied and both aspects can also condition the integration level (Bernardo et al., 2012a). There is scarce literature relating these three aspects of the process empirically (the majority of relationships are between two aspects, e.g. Labodová, ۲۰۰۴; Bernardo et al., 2012a). Thus, taking into account these results, the aim of this paper is to analyze the simultaneous implementation of an IMS in a small and medium-sized enterprise (SME). The costs of this implementation would also be analyzed. The contribution of this paper is to be one of the first empirical studies demonstrating that implementing an IMS is possible (different from the implementation of the two MSs at the same time), also in an SME, and it is profitable for the organization in terms of efficiency gained.