Background: Tobacco companies' strategies to promote tobacco use and undermine tobacco control policy are key in tobacco use among young people. The analysis of tobacco companies' internal documents can be instrumental in identifying those strategies, improving social support for tobacco control policy, and planning public health interventions. The goal of this study was to identify and analyze internal documents related to the activities of tobacco companies during the 1980s and 90s aimed at promoting smoking in young Spaniards. Methods: Electronic search by key word of tobacco industry documents held at the Legacy Tobacco Documents Library. Results: More than 1,000 documents were identified and reviewed, including letters, messages, memos, and other documents. Seventeen documents related to the objective of the study are analyzed and discussed. Conclusions: Tobacco companies funded and conducted activities aimed at maintaining high smoking incidence and prevalence in Spain. These activities, which included research, cigarette and packaging design, promotion, and social and political manipulation, may have had an impact on current levels of tobacco use in Spain.