Objectives: The Spanish Government has strengthened tobacco control policies since 2005, including changes in tobacco taxes. Because these changes have targeted cigarettes mainly, the tobacco industry has marketed cheaper alternative tobacco products, offering smokers the possibility to down-trade. This paper traces the evolution of patterns of demand for cigarettes and other tobacco products in Spain over the period 2005-2011 in order to assess the impact of such tax loopholes. Methods: We use data on tobacco products prices and sales as well as changes in the structure and levels of tobacco taxes to relate tax changes to price changes and subsequent market share changes. Results: Tax reforms have lifted the bottom end of the cigarette price distribution, but the industry has been successful in marketing fine cut tobacco at cheap prices. There have been partial attempts to correct this asymmetric tax treatment, but these have not avoided a remarkable increase in the market share of fine cut tobacco. The absence of a minimum tax on quantity for the rest of tobacco products allows the industry to place them as potential future down-trading vehicles. Conclusions: In order to address public health objectives, tax policies should aim to equalise the cost of smoking across different tobacco products. Otherwise the tobacco industry can exploit tax loopholes to market cheap alternatives to cigarettes. This requires all tobacco products to bear a minimum tax on quantity, whose levels need to be adjusted in order to reflect the equivalence between different forms of smoking. ; Support by Ministerio de Educación, project ECO2008-06395-C05-04, co-funded by European Regional Development Fund, and Fundación Séneca through project 08646/PHCS/08 is gratefully acknowledged (A. López-Nicolás and MB. Cobacho). Support by Instituto de Salud Carlos III, Government of Spain (RTICC RD06/0020/0089) and Ministry of Universities and Research, Government of Catalonia (Grant 2009SGR192) is gratefully acknowledged (E. Fernández).