This study addresses the strategic planning and environmental scanning activities of the hotel chains operating in Portugal, and compares attitudes towards planning and scanning activities by companies where strategy is formalised through a formal written strategic plan (intenders) and those companies where strategy is informally developed through a 'vision' or 'informal plan' (realisers). The main challenges facing Portuguese hoteliers as identified by the representatives of the Portuguese government, hotel associations and hotel chains inform the development of the study. The aims of the research derive from these challenges faced by the Portuguese hoteliers and their need for a more proactive attitude towards strategic planning, as well as from the literature on strategic planning and environmental scanning. The study is exploratory and descriptive based on a qualitative and inductive approach. This methodology is used to elicit and represent the existing practices as well as managers' perceptions towards strategic planning and environmental scanning. The fmdings reveal a lack of formal continuous environmental scanning by both formal and informal planning chains and a significant number of similarities in terms of the scanning methods and sources used by these two types of organisations. A grounded theory methodology is used to identif' the core themes emerging and to develop theory on the planning and scanning activities of hotel chains. The use of this methodology also allows a better understanding of the relationship between strategic planning and environmental scanning by hotel chains where strategy is intended (existence of a formal written strategic planning) and by those where strategy is realised (no existence of a formal written strategic planning). A cognitive mapping technique is used for the analysis of respondents' perceptions towards the development of a formal environmental scanning process. This technique is also applied in the identification of the relevance and structure of a formal environmental scanning process, in the assessment of the barriers to the development of this process as well as possible actions to overcome them. The study also finds that the existing differences amongst intenders and realisers rely essentially on aspects of content rather than on aspects of process, and that keeping a high degree of flexibility in the decision making process is considered of premium importance. The preponderance of similarities as opposed to differences lead to the development of a series of output propositions common to all four comparison groups. These propositions, together with other recommendations suggested in the literature, are used to identify the necessary conditions for the development and implementation of a continuous environmental scanning process by formal and informal planning hotel chains and develop a theoretical model of environmental scanning.