Some supporters of liberal drug politics in the whole world and in Lithuania try to suggest that usage of marihuana and other cannabis products is harmless and marihuana can even be used for medical purposes. They state that usage of cannabis products does not lead to usage of stronger drugs and so on. Other authors state that regular marihuana use always leads to trying stronger drugs and development of drug addiction. The aim of this study is to examine connection between regular marihuana use and other drugs, to find factors that motivate marihuana users to try other drugs, and to name differences of attitude towards drugs and drug addiction between regular and irregular marihuana users. The research was conducted in six vocational schools of Klaipeda; 912 freshman students (mean age 17.5 years) were surveyed. During the survey, anonymous questionnaires were administered, and data were processed using SPSS program package. During the study, it was established that 15.6% of vocational schools' males and 4.9% of females smoked marihuana often or more often (more than 20 times). Those students are regular marihuana users, and they already may need medical or psychological help. Behavior and attitude of regular marihuana towards drugs users, which can be named as tolerance towards all drug usage ideology, statistically significantly differed from ideology of irregular marihuana users. The following percentage of regular marihuana users have also tried other illegal drugs: 58.6% have tried psychostimulants in the form of pills or powder (amphetamine, ecstasy, LSD, and others), 20.0% have tried intravenous drugs, 19.2%--various other drugs, and 42.4%--alcohol with pills.