Women with lifelong vaginismus (N = 117) were randomly assigned to cognitive-behavioral group therapy, cognitive-behavioral bibliotherapy, or a waiting list. Manualized treatment comprised sexual education, relaxation exercises, gradual exposure, cognitive therapy, and sensate focus therapy. Group therapy consisted of ten 2-hr sessions with 6 to 9 participants per group. Assistance with minimal-contact bibliotherapy consisted of 6 biweekly, 15-min telephone contacts. Twenty-one percent of the participants left the study before posttreatment assessment. Intent-to-treat analysis revealed that successful intercourse at posttreatment was reported by 14% of the treated participants compared with none of the participants in the control condition. At the 12-month follow-up 21% of the group therapy participants and 15% of the bibliotherapy participants, respectively, reported successful intercourse. Cognitive-behavioral treatment of lifelong vaginismus was thus found to be efficacious, but the small effect size of the treatment warrants future efforts to improve the treatment.