 In the current study, two nurses or radiation therapists at each of the included hospitals will receive training in using MI in smoking cessation counselling. The Norwegian Directorate of Healths standard smoking cessation program based on MI will be modified to be appropriate for cancer patients in treatment. The Norwegian Cancer Society NCS will be responsible for the training and the adaptation of the program. NCS will cover on average a 50 percent position designated smoking cessation counselling at each cancer ward. Counselling one to one counselling will take place in connection with cancer treatment appointments, before or after preferably before as patients might feel unwell or nauseas after treatment, except for the first appointment that will happen before cancer treatment starts. Each counselling session will last for approximately 30-60 minutes. 