The purpose of this study was to investigate the determinants and factors influencing the motivation of alcohol dependents to undergo treatment. As well as exploring the influence of socio-demographic and illness-related variables, the study concentrated in particular on the influence of the clients' attitudes towards their current life situation, their alcohol problem and the treatment, also the influence of specific interventions aimed at increasing their motivation for treatment. On the basis of the results obtained in the study from 239 alcohol-dependent clients, it is shown to what extent these variables are of value as a means of predicting and modifying the motivation for treatment. In the motivation programme a variety of procedures was applied using a 2 x 2 design: motivation on an individual basis and motivation on a group basis were combined with two different approaches, one client-centred and one in accordance with the principles of cognitive-behavioural therapy. A group placed on a waiting list for 3 weeks was used as a control group. The clients were allocated to the various groups on a random basis. Specific attitudes on the part of the clients and aspects of the motivation programme provided significant indicators of the clients' likelihood to undergo treatment.(ABSTRACT TRUNCATED AT 250 WORDS)