This thesis contributes to the debate about the role of design and designers in a modern organisation. It aims to engage in academic dialogue through an exploration of the way designers perceive themselves and their methods (and also how they are being perceived); providing an outline of their professional culture and its interactions in an organisation. Its rationale is based on the assumption that various occupational and professional cultures can have significant influence on the way organisations are run. Thus, by examining the dimensions and sense-making within the professional culture of designers, this PhD aims to establish the analytical grounds for understanding the role design and designers in an organisational setting. By conducting a number of in-depth interviews with general managers, senior designers, management consultants and design managers from IDEO, Wolff Olins, Nissan Design and Philips Design this thesis looks at constructs attributed to designers that emerge at the core of their culture. Grounded theory methodology helped to establish a picture of the cultural arrangements in design-intensive organisations. 'Consolidating multidimensional meanings', `Creating bringing to 4/, Embracing discontinuityand gbenendedness', Embracing persona/ and commercial empathy', Engaging porensorial aesthetics', are the five theoretical categories that have been recognised as important to describing designers' professional culture. The analysis suggests that designers, by focusing on adding fundamental rake through unconfined exploration can play the part of 0/J-temological change agetas'in an organisation. Additionally, the thesis develops a model of design's influence on organisations. According to this model there are three 'channels' through which design affects organisations: (i) frameniarhs such as ontologies, epistemologies, theories, methods, tools, techniques etc., (ii) outcomes including physical artefacts, environments, brands and experiences, (iii) a'esigwers and their professional culture with certain values, assumptions, skills, preferences, behaviours etc. Designers, as a professional group, might have a more or less active roles within those groups of influences, modifying them in accordance with their culture