Global tourism is one of the world's largest industries, employing some 238 million people, generating over 10% of the world GDP, an annual growth rate of 4% and revenues expected to grow to $12 trillion by 2016. This important industry is an intensely competitive marketplace and, most importantly, characterised by an increasing difficulty in achieving differentiation. This, in turn, exacerbates the level of competition and limits viable response strategies. To cope with the increasing dynamism of the industry with particular reference to competitive intensity, fragmentation and differentiation, different augmentations of product/service bundles and strategies have been proffered. Prominently, the utilisation of co-marketing in parallel or in lieu of competition is increasingly prevalent, significant, and successful in product marketing. More recently, and to a lesser extent, it has been applied to domestic tourism marketing. Accordingly, this research is focused on pan country national level tourism collaborations and most specifically on developing a set of indicative selection criteria for country partners which reflect both marketing and organisational considerations and implications. Using a methods triangulation approach and building on theoretic corpus developed from marketing, organisational and behaviour literature, data collection involved the use of both questionnaire and in-depth interview methods. The questionnaire administration' was based on discretionary sample, selected from premier tourism events such as the international tourism trade exhibitions. Analyses of responses provided the basis for a series of subsequent personal interviews with strategic decision makers for national tourism such as tourism industry leaders and Ministers of Tourism of selected countries. On the basis of the intergrative findings from this research, a set of evaluative criteria for collaborative partner selection was developed. This set of criteria provides a template to evaluate potential collaborative partners reflecting both a spectrum of marketing considerations and organisational and behavioural perspectives . The criteria facilitates the design and selection of a co-marketing collaboration which provides a diverse, new and innovative basis for successful differentiation. The research reveals that arguments beyond purely rational decision making have a significant impact on collaborative decisions. Most specifically, political and vestiges of heritage based considerations were significant, prominent and prevalent. Similarly, the perception of which countries are competitors was often based on parochial perspectives. Thus, research substantiates the viability and efficacy of comarketing with the correct partner and its ability to create unique opportunities for marketing differentiations in an increasingly competitive and homogenious market place. However, there are some important caveats. While the benefits of collaboration are both established and significant, ambivalence and constraints based on subjective considerations are prevalent.