BACKGROUND. Despite much effort spent on antismoking programs in schools in different countries, limited effects have been observed in many cases. Evidence from European countries shows that active tobacco control actions such as ban on tobacco advertising, increase of tobacco taxes could lead to successful results. Our study was aimed to analyze time trends on smoking in Lithuanian school-aged children during the period of 1994-2006 in the context of antismoking policies, which were implemented in Lithuania. MATERIAL AND METHODS. This study was a part of WHO Cross-National Health Behavior in School-Aged Children (HBSC) study carried out in Lithuania. The standardized methods of international HBSC study protocol were applied. Stratified random representative samples of 5428, 4513, 5645, and 5632 students aged 11, 13, and 15 years were included into school-based anonymous questionnaire surveys in 1994, 1998, 2002, and 2006, respectively (spring semester). Questions on frequency of smoking, age of initiation and other questions were included. Response rates of each of these four questionnaire surveys were higher than 90%. RESULTS. Smoking behavior was more common among boys. The prevalence gap in smoking between boys and girls diminished during period of observation. Prevalence of smoking increased significantly among boys during the period of 1994-2002 (11.3%, 19.8%, and 23.6% in 1994, 1998, and 2002, respectively), but started to decline after (17.3% in 2006, P<0.05). Similar trends were observed among girls: 3.6%, 8.5%, 14.6%, and 12.5% of girls reported smoking in cross-sectional surveys of 1994, 1998, 2002, and 2006, respectively. Boys living in rural areas were more frequent smokers than those living in urban areas in 1994-1998 (9.5% vs 13.9%, P<0.05). However, the surveys of 2002-2006 showed opposite changes (25.6% vs 22.1%, P<0.05 and 17.8% vs 16.9%, P>0.05). Urban girls have reported smoking more frequently in comparison with rural girls. CONCLUSIONS. An increase in tobacco smoking among school-aged children was observed in Lithuania during 1994-2002. A decrease in prevalence of smoking was seen during the period of 2002-2006. These trends could be related to the implementation of tobacco control measures in Lithuania.