The effectiveness of a self help book on assertiveness training was assessed by comparing two bibliotherapy conditions with group therapy and a waiting list control condition. One group of bibliotherapy subjects read a popular paperback with no therapist contact, while the other group additionally participated in informal discussion sessions. Assessment instruments included self report measures of assertiveness and anxiety, as well as verbal role play responses to taped analogue situations. A small sample size and large dropout rate precluded definitive conclusions, but results indicated that both bibliotherapy procedures were essentially as effective as assertiveness trainnig group therapy. A near-significant decrease in anxiety was observed in subjects who became more assertive. (Author)