The aim of the current research was to examine the effectiveness of group multi-components cognitive-behavior therapy on insomnia severity and quality of sleep of breast cancer patients after surgerical operation. Applying an available sampling procedure and randome assignment method for assigning group samples, a sample of 30 breast cancer patients (experimental=15, control= 15) were selected. The criteria of inclusion and exclusion were checked for and the Pittsburgh Sleep Quality Index (PSQI) and Insimnia Severity Inventory (ISI) were completed by all subject in three occasions (pre, post and follow-up stages). The six session’s therapy protocol were conducted on experimental group, whereas another group received only simple meeting with the therapist. Data extracted from questionnaires and analysed using Multivariate Analysis of Covariance (MANCOVA). Significant differences were revealed for insomnia severity in the follow up stage, and for quality of sleep in the post-test and follow-up stages, between two groups with decreased mean scores in the experimental group than contol. Multi-components Cognitive-behavioral therapy could improve insomnia severity and sleep quality of patients with breast cancer after surgery and is recommended for these patients to resolve their insomnia problems.