Two standardized interviewing schedules have been administered to 850 chronic cannabis takers and 839 nontakers, all males, ranging in age between 15 and about 50 years. The present paper is concentrated on presenting data pertaining to temperamental characteristics prevailing among takers. Some characteristics were found not to differentiate between takers and control. This was true regarding two basic personality traits, acquiescence and 'emotional lability'; three situational characteristics, aggressiveness, sense of responsibility in matters of money expenditure and the degree on attaches to one's promises in work situations; one point concerning family background, viz, death of either parent; and lastly two aspects of the complex role fathers play in the lives of their children, which is 'absence--presence' and 'showing interest in the children's future'. The two groups differed on another collection of attributes. Compared with controls, cannabis takers were low on submissiveness, impulsiveness and negativism, but at the same time showed callousness or indifference towards the presence of others. Taker were, also, low on quarrelsomeness and high on selflessness but at the same time expressed more inclination towards dishonesty. Instability in the orientation family prevailed among takers who related more incidents of separation and/or divorce between parents, and of the existence of step-parents. Takers had, moreover, spoiling fathers.